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

Annotations already indicate read-only, non-destructive, idempotent behavior, but the description adds valuable non-obvious context: the record visibility timing and the expected 4xx without wait_seconds. This goes beyond schema and annotations, helping the agent interpret errors correctly. The explicit 'Side effects: none (read-only)' reinforces the read-only nature.

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 compact, front-loaded with the purpose, then gives parameter workflow, then side effects. However, it partially repeats the schema's wait_seconds explanation, which introduces slight redundancy. Overall, every sentence earns its place, but the duplication with the schema prevents a perfect score.

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 tool with an output schema, the description does not need to explain return values. It covers purpose, workflow, expected errors, and side effects. With only one required parameter and full schema coverage, the description is complete enough for correct invocation and interpretation.

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 coverage is 100%, so the baseline is 3. The description repeats the wait_seconds default and usage pattern already present in the schema, adding no new semantic information. It does not introduce any parameter meaning beyond the schema, so a baseline score 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?

Description states a specific verb ('Get details') and resource ('fax scheduled for sending (outbox)'), which clearly indicates the tool's scope. While it doesn't explicitly name a sibling, the 'outbox' qualifier distinguishes it from similar tools like get-fax. It is clear and unambiguous, though it could have explicitly contrasted with related tools.

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?

Provides concrete workflow guidance: after send-fax-uploaded, pass wait_seconds=30 on the first check, omit for later polls, and treats immediate 4xx as expected. This is strong when-to-use guidance, but it does not mention alternatives or explicitly state when not to use this tool. The instructions are actionable and sufficient for the intended flow.

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