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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered structurally; the description still adds cost context ('free') and the key behavioral detail that returned ids map to full documents (implying a separate retrieval step). It does not disclose rate limits or result-count/pagination behavior, so it is not 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?

Two sentences, verb-and-scope front-loaded, with the indexed content enumerated in a single compact list and the return shape appended last. Every clause adds discriminating information about what this tool searches.

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?

An output schema exists so the return shape needn't be re-explained (though it is), and annotations carry the safety profile, leaving the description to cover scope and content, which it does thoroughly. The only gap is the absence of explicit routing guidance to the sibling retrieval tool.

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?

There is a single parameter ('query') at 100% schema description coverage, so the schema already carries the meaning and the baseline is 3. The description does not add syntax, format, or example guidance beyond the schema's 'plain words' 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 (searches) and a precisely scoped resource (GBLIN's documentation and live state), then enumerates exactly what is indexed: agent API summary, protocol README/governance/deployments/review record, MCP server and library READMEs, public pages, one card per MCP tool, and live vault state. This is far more specific than the sibling tool names, so an agent can tell it is the general retrieval entry point rather than a domain-specific state tool.

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 rather than stated: it is the general documentation/state search, and the note that each id identifies a full document hints at a follow-up fetch, but no explicit when-to-use, when-not-to-use, or named alternative (e.g. the 'fetch' sibling) is given. An agent must infer the routing.

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