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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds that this is a pure boolean check, that the bearing must be passed through untouched, and that the id is echoed back. It does not say whether an invalid or tampered bearing yields verified=false versus an error, which is the one behavioral detail an agent would want.

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 short sentences, front-loaded with the action, then inputs, then return values. Every sentence carries information; no filler or repetition of the title.

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?

Two parameters, full schema coverage, and no output schema — yet the description explicitly enumerates the return shape (verified and id), which compensates. The only gap is the error/false distinction, minor for a read-only checker.

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 100% and both parameter descriptions already state 'from source_fetch_fragment, unchanged' and 'echoed back', so the description largely restates the schema. The emphasis on pass-through is useful reinforcement but adds no new syntax, format, or failure semantics. Baseline 3 applies when the schema carries the detail.

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 (checks/verifies) applied to a specific resource (the bearing from source_fetch_fragment), and names the outcome (verified true/false). An agent can distinguish it from source_fetch_fragment, which produces the bearing rather than checking it. It stops short of saying what the check actually validates (integrity? cryptographic proof? citation match), so 'checks' stays slightly opaque.

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 sentence 'Checks the bearing returned by source_fetch_fragment' establishes the prerequisite and the fetch-then-verify sequence, and 'exactly as source_fetch_fragment returned it' warns against reconstructing the value. There is no explicit when-not guidance, but no sibling overlaps meaningfully in scope, so context is adequate.

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