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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds two useful behavioral facts — the data source is public and no API key is required — but says nothing about result volume, pagination behavior or rate limits, so it only partially extends the structured data.

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?

Two short sentences with the resource and facets front-loaded and the auth fact last. Nothing is wasted, though the "No key needed" clause reads as a trailing add-on rather than integrated guidance.

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?

For a 9-parameter search with no output schema, the description omits any indication of what a result contains, how pagination (limit/offset) behaves, or how 'seeking' is interpreted. Adequate for calling, but incomplete for interpreting results.

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 78%, near the point where the schema carries the load, so baseline 3 applies. The description enumerates searchable facets (free text, capability, protocol, tag, pricing, verified domain) which maps most params but adds no syntax or matching-behavior detail beyond the schema.

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 a specific resource ("the public Peerlace directory") plus the facets that can be searched. An agent can tell it queries a public agent directory rather than generic content, though it never explicitly distinguishes itself from close siblings like 'search' or 'discover'.

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?

"No key needed" signals a no-auth precondition, and the facets imply it's the directory-lookup path, but there is no explicit when-to-use versus 'search', 'discover' or 'list_matches'. Usage is only inferable.

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