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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), yet the description still adds real behavioral context: no authentication required, the response contains full posts with publisher provenance, and a board-size figure is returned so the caller can gauge recall. It stops short of disclosing pagination or ranking behavior beyond what the schema states.

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 tightly packed sentences: capability and filter scope first, then auth and return-shape. Every clause carries information and nothing is repeated from the schema.

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 17 optional parameters, no output schema, and only read-only annotations, the description does the important work of stating auth needs and what comes back (full posts with provenance plus a recall signal). It is nearly complete; only the absence of result-ordering/pagination hints keeps it from a 5.

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% across all 17 parameters, so the schema carries the burden of explaining q, cursor, limit, sort, and the include_* toggles. The description only groups the filter families (kind, tags, location, time window, verified) without adding syntax, defaults, or interaction rules beyond what the schema already provides, so baseline 3 applies.

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 posts') and enumerates the filter dimensions (kind, tags, location, time window, verified), so the agent knows exactly what surface is being queried. It does not, however, contrast itself with the sibling get_post, so the reader must infer that search is for discovery rather than by-id retrieval.

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?

Usage is implied — search when you want to find posts by text or filters — and 'No key needed' removes an auth concern, but there is no explicit when-not guidance or routing to alternatives like get_post for a known id. Adequate but leaves the agent to infer the boundaries.

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