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

Annotations already declare readOnly, idempotent and non-destructive, so the bar is low, yet the description still adds real signal: results are only populated when status is COMPLETED, and the payload enumerates detection windows, matched title/artist, and a publish-safety verdict. It does not state what is returned in non-COMPLETED states.

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 tightly written sentences, front-loaded with the core action, followed by exactly the conditional detail an agent needs. No filler or redundancy.

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, the description carries the return-value burden and does so well by describing the detection windows, matched metadata, and verdict. For a simple read-only, single-parameter tool, 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 100% and the single uuid parameter is fully documented in the schema, so the description is not required to compensate. It adds only the loose hint that a screening is identified by that id, which is baseline value.

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 (fetch) and resource (one screening's status and result), and the singular scope implicitly separates it from the plural list_screenings sibling. It stops short of naming any sibling or the condition that routes to it, so differentiation is inferable rather than explicit.

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 usage (retrieve a known screening by id) and notes the meaningful state is COMPLETED, but never says when to use this versus list_screenings, screen_audio, or verify_report, nor any exclusions or prerequisites.

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