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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description isn't burdened there. It does add behaviorally useful detail absent from structured fields: a fixed cardinality of 10 and the three attributes returned, which matters because there is no output schema. No auth, rate-limit, or pagination notes, but neither is relevant for a static enum-like list.

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, no filler. The contents of the result are front-loaded ahead of the when-to-call guidance, which is the right order for a listing tool.

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?

A zero-parameter, no-output-schema lookup tool; the description states the count, the fields returned, and the call condition, which is everything an agent needs. The link to studio_link closes the loop on how the output is consumed.

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?

Zero input parameters, so the baseline is 4 and there is nothing the description could add on that axis. It correctly adds the output-side meaning (id maps to the 'style' argument of studio_link), which is the only relevant parameter semantics here.

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 plus resource: 'Lists the 10 Cuecaps caption styles', and it enumerates exactly what comes back (id, name, appearance). It also explicitly ties the result to the sibling tool by naming 'style to studio_link', so an agent can separate the two without opening schemas.

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 an explicit invocation condition ('when the user hasn't picked a style or asks what the styles look like') and implicitly excludes the case where a style is already chosen. The downstream consumer (studio_link) is named, so the ordering relative to the sibling is inferable.

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