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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds value beyond them by disclosing the account/auth requirement and by describing what results contain (onset/peak/tail timing in ms, LUFS and true peak, conditional on the sound having been analysed).

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?

Three dense sentences with zero filler, front-loaded with the what, then the prerequisite, then the practical query constraint, then the result shape. Every sentence earns its place.

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 read-only, no-required-param search tool whose annotations cover safety, the description supplies the missing pieces: auth prerequisite, matching semantics, and return-field content in the absence of an output schema. Minor remaining gaps are pagination/sort behavior and what error surfaces when no account is connected.

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 only 56%, so the description needs to carry weight, and it does: it explains the AND-matching semantics of q (every word must match name, description or tag), the role of tags and max_duration for narrowing, and the duration filter. It leaves page/sort/order/limit to the schema, but those are largely self-explanatory or documented there.

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 ('Search') and resource ('Lots of Sounds CC0 catalog') and enumerates the searchable facets (keyword, tags, category, duration), which is more than a restatement of the title. It does not explicitly differentiate itself from the sibling browse_samples, so an agent must infer the search-vs-browse boundary.

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 actionable query-building guidance ('Each word in the query must match... so use short keywords and narrow the search with tags or max_duration') and a prerequisite ('A connected account is required'). It stops short of naming an alternative tool or stating when not to use it (e.g. when to prefer browse_samples).

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