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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so 'Read-only' is redundant. The added value is 'free' (cost profile) and the enumeration of what the document corpus contains, but auth/permission and error behavior are not covered.

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 tight sentences, front-loaded with the action and resource, then the corpus clarification. No filler sentences; 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?

An output schema exists so return values need not be explained, and annotations carry the safety profile; the description nonetheless names the returned fields and the document types. Complete enough for a single-parameter read tool, with only id-discovery guidance missing.

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% and the schema even supplies an example id ('protocol-readme'), so the parameter is already well documented. The description adds little beyond confirming 'by its id'. Baseline 3 is appropriate.

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: fetch one GBLIN document by id, and clarifies the corpus (protocol docs, tool cards, live vault state). The singular 'one ... by its id' implicitly separates it from the sibling 'search', though that alternative is never named.

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 by the required id parameter, but there is no explicit when-to-use guidance, no mention of how to obtain an id, and no reference to the 'search' sibling that would supply one. The agent must infer the fetch-by-known-id workflow.

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