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

Annotations already declare readOnly/idempotent/non-destructive, so the description correctly spends its words elsewhere: it discloses the critical aggregation caveat that unnamed speakers collapse into a single 'unnamed' bucket because 'Speaker 1' is a different person per recording. That is exactly the kind of non-obvious behavior an agent would otherwise get wrong; it only lacks notes on ordering or cost of the aggregation.

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 definition and return shape, then the unnamed-speaker caveat, then the filtering hint — a sensible ordering. Slightly long and the bilingual example query is a nice touch but adds a little bulk; nothing is genuinely wasted though.

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?

An output schema exists, so the description needn't fully spec the return values, and it still summarizes the key ones. With 15 optional parameters and 100% schema coverage, the remaining need is behavioral guidance, which the unnamed-speaker note and filter hint supply. Missing only edge details like default ordering or behavior when no speakers match.

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 every one of the 15 parameters is already documented in the schema, including the enum values and ISO-8601 formats. The description only name-drops projectId and startedAfter as suggested filters, which is usage advice rather than added parameter meaning, so the baseline 3 applies.

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 and resource ('Lists the people in the user's recordings') and goes further by naming exactly what is returned per speaker: recording count, segment count, and last-spoken time. No sibling tool covers speaker aggregation, and the example queries ('who do I meet with most') make the intent unmistakable.

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 two example utterances give an agent a concrete trigger pattern, and 'Works well with a filter such as projectId or startedAfter' tells it to scope the call rather than enumerate everything. It stops short of naming an explicit alternative or a when-not-to-use condition, so it falls just short of 5.

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