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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open world), so the description's added value is the disclosure that the payload includes the de-identified narrative, coded fields, and official synopsis — useful for anticipating output. It doesn't mention any rate limits, auth requirements, or what happens on an unknown ACN, so it stops short of full disclosure.

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?

Two sentences, zero filler: the first defines the resource and its contents, the second routes from the sibling tool. The identification of the resource is front-loaded before the usage note.

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 lookup with no output schema, the description compensates by enumerating the returned fields (date, airport, state, aircraft, flight phase, anomaly types, contributing factors, synopsis). Combined with full annotation coverage, an agent has everything needed to call it and anticipate the response.

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% and the single parameter is documented there, so the baseline is 3. The description adds marginal value by confirming the ACN is the same identifier returned by asrs_search, tying the parameter to its upstream source rather than just its format.

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?

Specific verb ('Fetch') plus resource ('one NASA ASRS aviation safety report') plus the exact identifier ('ACN'), with scope narrowing to a single record. It also enumerates what comes back (full narrative, coded fields, synopsis), which makes it clearly distinct from asrs_search's excerpt-style results.

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?

Explicitly sequences the tool after asrs_search ('Use after asrs_search returns a report's ACN') and names the condition that selects this tool ('need the complete narrative rather than the excerpt'). The alternative and the switch condition are both stated, not inferred.

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