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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real value: it discloses the visibility model (public approved + owned/administered private), the exact fields matched by query, and "Free; calls no API." Only the result ordering and pagination behavior are left unstated.

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 tight sentences, front-loaded with scope, then matching semantics, then return shape and cost. Every clause carries information an agent needs; nothing is restated from the title or annotations.

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 an output schema present, the description needn't enumerate return values, though it helpfully summarizes them. For a zero-required-parameter search tool it is nearly complete, with the only gap being how `limit` and result ordering behave across larger result sets.

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 50%, so the description must partially compensate. It does well for `query`, spelling out which fields are matched and that matching is case-insensitive, but says nothing about `category`, `datasource_type` (which has an enum), or `limit`, leaving half the parameters to the schema alone.

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 ApiClay marketplace") and immediately scopes it: public approved APIs plus private APIs you own or administer. The verb/resource pair cleanly separates it from the siblings, which describe and invoke a single API rather than search.

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?

Implies the discovery-then-invoke workflow by noting the returned vendor usernames feed apiclay_describe_api and apiclay_call_api, which tells an agent where this tool sits in a sequence. It does not state explicit when-not conditions (e.g., use describe_api if you already know the vendor), so it falls short of a 5.

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