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

Adds substantive behavior beyond annotations: it discloses what is returned (matched license/resource, the understood use, and a deterministic answer with reasons), that it asks for clarification rather than guessing, and that it is free with no key. The clarification behavior and the 'verify the understood use' caveat are the kind of context annotations cannot express. It does not address the readOnlyHint=false side effect (persisting the assessment when a key is supplied).

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?

Front-loads the call condition, then the return shape, then the caution and cost note. Four sentences, each doing work, though the middle sentence packs several ideas together.

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 detailed, yet the description still summarizes them helpfully. Combined with annotations covering safety and a well-documented nested schema, an agent has enough to call correctly; only the routing versus similar siblings remains implicit.

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 75%, with rich inline docs for intended_use flags and resource_id, so the schema carries the burden. The description only alludes to these inputs indirectly ('the license or registered resource', 'the use it understood') without adding format or semantic detail. 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 capability: answering rights/licensing questions phrased in plain English, with a concrete example ('Can I use CC BY-NC 4.0 images in a paid ad campaign?'). The 'plain English' framing implicitly distinguishes it from structured siblings like check_license and assess_resource_for_use, but no sibling is named explicitly.

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?

Gives a clear trigger condition ('Call when you have a rights or licensing question in plain English') plus a worked example, and adds a post-call caution ('Check the understood use before relying on it'). It does not name alternatives or state exclusions, so the agent must infer that structured checks belong to the sibling tools.

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