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

Annotations already cover readOnly/idempotent/non-destructive, yet the description adds substantial behavior beyond them: full status enum, retry-on-busy/unanswered/dropped semantics with attempt counts and ~17 minute window, and the field set surfaced on failure. This is exactly the polling and retry context an agent needs.

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-loaded with the core purpose, then statuses, then polling, then retry, then failure payload. Dense but each sentence carries distinct information; the failure-field enumeration edges toward restating what the output schema likely covers.

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 one-parameter polling tool with an output schema carrying return values, the description covers everything an agent needs: what it returns, when to stop polling, how retries behave, and what failure states mean. Nothing material is 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 coverage is 0% and the single required parameter is undocumented in the schema (no description, format only shown via example). The description implies job_id identifies a send_fax job but adds no format, source, or reuse guidance, so the gap is only partially compensated.

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 verb+resource: retrieve delivery status and receipt for a send_fax job. Naming send_fax as the originating job makes it immediately distinguishable from send_fax (which creates) and from the generic get_job sibling.

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 explicit operational guidance: poll about every 20 seconds and stop when status is delivered, failed or expired. It implies the post-send context but never explicitly states 'use this after send_fax' or names any alternative for other job types.

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