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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuine context the annotations do not: the data is drawn from the Official MCP Registry, meaning scope is limited to publicly registered servers, and results are compact summaries rather than full records. Pagination/limit behavior is not described, but the provenance disclosure is real added value.

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?

Three short sentences, front-loaded with the core action, then the return-shape caveat, then provenance. Every sentence earns its place and nothing is padded.

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 usefully states what comes back (compact summaries) and where to go for the full record. It also discloses the data source. Only minor gaps remain, such as ranking or result-cap behavior, which the limit parameter schema partially covers.

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 description coverage is 67%, so the schema documents most parameters (limit, publisher, transport, has_remote). The description only reinforces the query parameter's natural-language intent ("by what you want a server to do") and says nothing about the nested filters object, adding little beyond what the schema already carries.

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 (search) and resource (the public MCP server universe) and the axis of search (what you want a server to do). It explicitly distinguishes itself from the sibling get_server by noting it returns compact summaries rather than a full record.

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?

It routes the agent clearly: use this for discovery, then call get_server for a full record, which is an explicit alternative with its selecting condition. It stops short of stating when not to search at all (e.g., when the server name is already known, skip straight to get_server), so it is clear context rather than full when/when-not guidance.

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