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

With no annotations provided, the description carries the full burden and does so well: it discloses whole-word, case-insensitive, AND matching semantics and explains that name matches rank above description-only matches. This is substantial behavioral detail beyond the basic search action.

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 tightly written sentences: the core action comes first, then matching rules, then the prerequisite. Every sentence earns its place with no filler or repetition of schema details.

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?

Given no output schema and no annotations, the description still covers the essential contract: what is searched, how results match, how ranking works, and how to obtain a valid group slug. Parameter constraints are already in the schema, so no obvious gap remains for a keyword-search tool.

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 100%, so the baseline is 3. The description adds genuine value by explaining how query keywords are matched and by tying the group parameter to list_groups, going beyond the schema's terse field descriptions.

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 and resource: 'Search the mcpnav directory of MCP servers by name/description keywords,' and adds the optional category-group filter. This clearly differentiates it from siblings like get_server and list_groups even without naming them.

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?

Provides clear operational context by instructing the agent to 'Call list_groups first if you want a valid `group` value,' which ties the search to a prerequisite. It does not explicitly contrast this tool with get_server or list_groups, so full when-to-use vs. alternatives guidance is absent.

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