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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: it discloses that results include before/after values, observation time, source-as-of date, and raw snapshot hash, which tells the agent what kind of data to expect. It does not contradict 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?

The description is a single, information-dense sentence that front-loads the core purpose and then lists the specific data elements returned. Every clause earns its place; there is no filler or repetition of schema details.

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?

For a read-only, single-parameter tool with 100% schema coverage and no output schema, the description is largely complete. It explains what data is returned and the scope. It could be slightly more complete by explicitly noting that the tool is for historical observation/transition data versus current status, but the phrase 'profile transitions observed' already conveys this.

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 schema already documents both parameters (license_number and limit). The description adds the context that license_number is an exact Washington contractor license number, which is already in the schema. The description does not add significant meaning beyond the schema, so 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?

The description states a specific verb ('Return') and resource ('one Washington contractor license'), and enumerates the exact data dimensions: material status, expiration, specialty, and profile transitions. It clearly distinguishes itself from siblings like wa_contractor_verify and wa_contractor_recent_changes by focusing on historical transitions with before/after values.

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 description implies this is the tool for historical profile transitions of a single Washington contractor license, and the sibling list includes wa_contractor_verify and wa_contractor_recent_changes which are likely alternatives. However, it does not explicitly state when to use this tool versus those alternatives, nor does it state exclusions.

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