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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds genuine value beyond that by stating curation scope and the domain-authority ordering, and by explicitly disclaiming side effects. It does not describe result shape or paging behaviour, which keeps it below a 5.

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: purpose and ordering first, optional filter second, read-only caveat and intended use last. Nothing is repeated from the schema verbatim and every clause adds information.

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 two-parameter, read-only reference list with no output schema, the description covers what the tool returns conceptually and when to use it. The main residual gap is the undocumented `limit` cap of 71 and any truncation behaviour, which an agent cannot discover from structured fields.

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 only 50%: `category` is documented in the schema and the description reinforces it with concrete examples ('saas', 'ai', 'tools', 'dev'). The `limit` parameter has no documentation anywhere, and the unusual maximum of 71 and its default of 25 are left unexplained, as is any paging behaviour.

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: 'List curated directories a product can submit to, sorted by domain authority.' That is far more informative than the name alone. It never explicitly contrasts itself with near-neighbours like list_public_listings or list_tracked_sites, so the agent must infer the difference.

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 a clear use case ('Use to suggest where a product should get listed') and an explicit exclusion by clarifying it is reference data only and does not submit anything. It stops short of naming the submission alternative or listing when-not-to-use conditions, so it is strong but not complete routing guidance.

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