Get one claim with its limits and what would refute it

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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the bar is lower and credit goes to added context. The description adds a genuine behavioral guarantee — 'always present — what it does NOT establish and the observation that would retire it' — which tells the agent that falsification info is a non-optional part of the tool's contract. No contradiction with annotations.

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 with zero filler. The first sentence front-loads the resource, retrieval key, and full return shape using a colon list and em-dash emphasis for the 'always present' guarantee; the second sentence carries the usage guidance. Every clause earns its place, and the structure mirrors the tool's purpose of honest, limit-aware retrieval.

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?

Given an output schema exists (so return values need not be described), rich annotations cover the mutation/safety profile, and parameter coverage is 100%, the description supplies what remains: the retrieval key format, the guaranteed content shape, and the two legitimate workflows. Nothing an agent needs to invoke this tool correctly or route itself to it is 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%, so the baseline is 3 per the rubric. The description reinforces the id parameter by giving the concrete example format 'HE-CLAIM-001' and mentioning slug as an alternative, but it does not add substantive meaning beyond what the schema properties already document. It adequately confirms but does not compensate for any gap, because there is no gap.

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?

The description opens with a specific verb and resource — 'Get one claim by id (HE-CLAIM-001) or slug' — and enumerates exactly what is returned: the statement, what it rests on, structured sources, what it does NOT establish, and the observation that would retire it. This distinctive return contract (limits + refutation) clearly separates it from sibling get_* tools that fetch other resource types such as patterns, articles, or architectures.

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 second sentence gives explicit use cases: 'Use this to cite the corpus honestly, or to check whether a result you have just measured confirms or falsifies a claim it makes.' This is clear contextual guidance that positions the tool relative to a workflow, though it does not explicitly name alternatives (e.g., list_claims for enumeration) or state when-not-to-use conditions.

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