See whether your MCP tools actually work for the models calling them — retries, empty answers, schema cost and first-call success. Two lines to install.https://getmcpulse.com/https://getmcpulse.com/blog/what-mcp-servers-cannot-tell-you/https://getmcpulse.com/blog/what-mcp-servers-cannot-tell-you/You ship a server, it gets listed, people install it. From that moment on you are working blind — and the directories report almost none of what you need.Tue, 11 Aug 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/first-call-success/https://getmcpulse.com/blog/first-call-success/Uptime grades your infrastructure. Error rate grades your code. First-call success is the only metric that grades the thing you actually wrote for the model — the words.Tue, 04 Aug 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/empty-results-are-failures/https://getmcpulse.com/blog/empty-results-are-failures/An empty array is a 200. The model got nothing it could use, the user got a shrug, and no error was recorded anywhere. These are the failures nobody reports.Tue, 28 Jul 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/schema-tokens-every-session/https://getmcpulse.com/blog/schema-tokens-every-session/Descriptions and JSON Schema go into the context window at the start of every conversation. Twelve tools can cost 3,000 tokens before anyone asks a question.Tue, 21 Jul 2026 00:00:00 GMTTool designhttps://getmcpulse.com/blog/dead-tools/https://getmcpulse.com/blog/dead-tools/Every server has at least one. It costs schema tokens on every session, competes for the model's attention, and returns nothing, because nobody has ever reached it.Tue, 14 Jul 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/crashed-vs-tool-error/https://getmcpulse.com/blog/crashed-vs-tool-error/The MCP SDK catches whatever your handler throws and turns it into isError: true. From outside the request handler, a bug and a deliberate error are the same object.Tue, 07 Jul 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/bad-args-is-a-schema-problem/https://getmcpulse.com/blog/bad-args-is-a-schema-problem/When arguments fail validation, the instinct is that the model got it wrong. Usually the schema asked for something the model had no way to know.Tue, 30 Jun 2026 00:00:00 GMTTool designhttps://getmcpulse.com/blog/why-we-hash-arguments/https://getmcpulse.com/blog/why-we-hash-arguments/Twelve hex characters of a SHA-256 over the arguments, keys sorted. Enough to tell whether two calls were the same, and not enough for anything else.Tue, 23 Jun 2026 00:00:00 GMTPrivacyhttps://getmcpulse.com/blog/not-a-proxy/https://getmcpulse.com/blog/not-a-proxy/A proxy is the easier product to build and the wrong one to ship. Directory-listed servers cannot change their URL, and OAuth breaks the moment traffic is redirected.Tue, 16 Jun 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/percentiles-cannot-be-summed/https://getmcpulse.com/blog/percentiles-cannot-be-summed/You cannot average two days of p95 and get the week's p95. Four counters can be added across any range and still tell you the truth.Tue, 09 Jun 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/sessions-cross-midnight/https://getmcpulse.com/blog/sessions-cross-midnight/Bucketed counters are how a dashboard stays fast. But some things are not buckets, and summing them by day quietly double-counts every one that spans two.Tue, 02 Jun 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/what-a-heavy-response-costs/https://getmcpulse.com/blog/what-a-heavy-response-costs/Roughly 2,500 tokens, about a cent, and a chunk of the context window that the rest of the conversation no longer has. The last one is the expensive part.Tue, 26 May 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/writing-tool-descriptions/https://getmcpulse.com/blog/writing-tool-descriptions/The model reads your description once, alongside forty others, and decides immediately. Everything that makes documentation good makes a tool description worse.Tue, 19 May 2026 00:00:00 GMTTool designhttps://getmcpulse.com/blog/the-nightly-pass/https://getmcpulse.com/blog/the-nightly-pass/Three of the sixteen metrics need to see what came after a call. That is not knowable when the call arrives, so it happens overnight — and the dashboard says so.Tue, 12 May 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/rollups-exist-so-events-can-be-deleted/https://getmcpulse.com/blog/rollups-exist-so-events-can-be-deleted/Every call is written twice — once as a row you will throw away, once as a counter you keep forever. The second one is what makes the first one disposable.Tue, 05 May 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/naming-tools/https://getmcpulse.com/blog/naming-tools/The model has your tool name, your description, and nothing else. No source, no docs site, no colleague to ask. The name is doing more work than you think.Tue, 28 Apr 2026 00:00:00 GMTTool designhttps://getmcpulse.com/blog/instrumentation-must-never-break-it/https://getmcpulse.com/blog/instrumentation-must-never-break-it/The SDK runs inside someone else's production server. Three rules follow from that, and none of them are negotiable — including handing the server back unmodified.Tue, 21 Apr 2026 00:00:00 GMTEngineeringhttps://getmcpulse.com/blog/tool-pairs/https://getmcpulse.com/blog/tool-pairs/Models chain tools. When two of yours are always called in sequence, that pattern is usually a design note you have not read yet.Tue, 14 Apr 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/cost-per-session/https://getmcpulse.com/blog/cost-per-session/Not the monthly bill — that measures how popular you are. Cost per session measures how expensive you are, which is the part you control.Tue, 07 Apr 2026 00:00:00 GMTMeasurementhttps://getmcpulse.com/blog/passing-a-security-review/https://getmcpulse.com/blog/passing-a-security-review/If your MCP server touches customer data, someone will eventually ask what your monitoring vendor receives. These are the questions, and the answers that end the conversation.Tue, 31 Mar 2026 00:00:00 GMTPrivacy