Public MCP server status

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the readOnly/openWorld/idempotent annotations: it discloses result count and ranking (up to 5, exact name first), the exact fields returned, an explicit data-minimization guarantee ('Only names, dates and counts are returned, never tool descriptions'), and a critical interpretive caveat that an unchanged server is not proof of safety. That last point materially changes how an agent should report results.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then usage, then input, then return shape, then a caveat — a logical order with no filler sentences. It is somewhat long and enumerates return fields inline, but each sentence carries information an agent needs.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description fully covers the return contract (fields, cap, ordering, history link) and the limitations of interpreting a 'no change' result. An agent has everything needed to call it and to phrase its answer accurately.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description adds semantics the schema lacks: partial names are accepted ('or part of one') and results are ranked with the exact match first. It also supplies a concrete npm-scoped example beyond the schema's shorter one.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (look up), resource (a public MCP server in the signed public log kept by mcp-pin), and the exact question it answers (whether tool definitions changed and when). This is distinguishable from siblings like mcp_pin_my_servers and mcp_pin_change_summary without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit triggering conditions: 'Use it before installing or approving an MCP server, or when the user asks if a server changed.' Clear when-to-use context, but it does not name a sibling alternative (e.g. mcp_pin_change_summary) or state when this tool is the wrong choice.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.