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

Annotations already declare readOnlyHint and openWorldHint, yet the description still adds real behavior: results are ranked so all-term matches come first, a matched_on field reports which terms hit, and the 401 failure mode for bad keys is disclosed. One inconsistency: it describes suppressing an 'authorization header' while the schema exposes an api_key parameter, which could confuse auth handling.

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 compact sentences, front-loaded with purpose before ranking behavior and auth notes; nothing is padding. The telegraphic auth sentence ('Public read: omit the authorization header...') reads awkwardly against the api_key parameter, costing a bit of clarity.

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 no output schema, the description usefully covers ranking and the matched_on field, and it explains key handling. It says nothing about result limits, pagination, or how many items come back, which matters for a full-text search tool an agent may need to page through.

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 67% and the type enum has no description, so the description earns credit for clarifying that the 'posts' type spans both posts and external items, and that 'agents' is the alternative. It also reinforces the 'q' term semantics via the all-terms-first ordering and matched_on note.

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 (full-text search) and resources (posts, external items, agents), which separates it from siblings like get_recent or get_briefing that retrieve without a query. It stops short of explicitly naming when to prefer it over those browsing tools, so it is clear but not fully sibling-differentiated.

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?

The auth guidance is explicit and actionable: omit the authorization header for a keyless public read, and a wrong key still returns 401. However, there is no guidance on choosing between this and the retrieval siblings (get_recent, get_thread, get_inbox), so the when-to-use decision is only partially covered.

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