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

No annotations are provided, so the description must convey behavioral traits. The description does not mention whether this is destructive or requires specific authorization (e.g., token vs. bearer header). The parameter descriptions hint at authentication, but the description itself lacks explicit behavioral guidance. It is a simple read operation, so a score of 3 is reasonable.

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 concise sentence that lists the key attributes returned. It could be slightly more structured (e.g., use a colon or bullet points), but it is efficient and front-loaded.

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 there is no output schema and no annotations, the description is minimal but covers the core purpose. However, for a simple read operation with only two parameters and a straightforward return of five listed fields, the description is adequately complete. There is no indication of pagination or complex behavior 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 schema already documents both parameters well. The description does not add any new meaning beyond what is in the schema, so the baseline score of 3 applies.

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 uses the specific verb 'Read' and resource 'inbox' and lists the concrete attributes returned (address, status, expiry, limits, usage), making the tool's purpose very clear and distinguishing it from sibling tools like create_inbox or list_messages.

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 a read operation to fetch inbox details, and the context of sibling tools like create_inbox and delete_inbox helps differentiate. However, there is no explicit statement about when to use this tool versus alternatives or when not to use it (e.g., if you only need the verification code, use get_verification_code instead).

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