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

No annotations are provided, so the description must disclose behavioral traits. It only mentions permission requirements but omits details like return format, error handling, rate limits, or destructive potential. This is a significant gap for an agent deciding to invoke the tool.

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 efficient sentence that front-loads the main action and constraint. However, it could benefit from additional structured detail without losing conciseness.

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?

With no output schema, no behavioral details, no parameter descriptions, and 6 parameters including optional ones, the description is severely incomplete. An agent would struggle to understand how to properly provide inputs like 'imageBase64' or which 'type' to choose for a given CAPTCHA.

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?

The schema has 6 parameters with 0% coverage in descriptions. The description adds no explanation of parameter meanings, such as the enum values for 'type' (e.g., differences between recaptcha_v2 and image_text). Despite the self-explanatory names, the lack of guidance forces the agent to guess correct usage.

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 clearly states the tool solves a CAPTCHA for owned/permitted domains. It uses the specific verb 'solve' and resource 'CAPTCHA', and the permission constraint distinguishes it from related tools like agent_captcha_verify_domain.

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 'for a domain you own or have explicit permission to access' provides clear context on when to use the tool (i.e., when authorized). It implies exclusions for unauthorized domains, though no explicit alternatives or 'when not to use' guidance is given.

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