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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real context beyond that — the content is 'generated from the same lists the editor uses,' making it authoritative ground truth, and it signals that how_to_choose performs wish-to-setting translation. It does not describe shape or size of the returned payload, but an output schema exists, so that omission is minor.

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 purpose and ends with the actionable directive, so the important parts are where an agent will read them. The long parenthetical area list is somewhat redundant with the enum and inflates the sentence, which keeps it from a 5.

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 two-parameter lookup tool with full schema coverage, complete annotations and an output schema, the description supplies what structured fields cannot: provenance, authority and a usage rule. Remaining gaps (payload size, behavior for an invalid listingId) are minor for this tool type.

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 baseline is 3, but the description adds meaning beyond the enum labels: it names what each area covers in plain language ('music styles and trimming', 'photo edits and staging') and explains what the how_to_choose value actually does. It does not explain listingId, though the schema already ties it to list_listings.

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?

'The product guide: every option the Studio has for one area, in the Studio's own words' is a specific resource plus scope, and the enumerated areas (title designs, text, stickers, camera and timing...) make it clearly a reference/catalog tool rather than an action tool like add_text or list_music. It falls short of 5 only because the purpose statement is buried in a long run-on enumeration rather than stated crisply up front.

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 explicit operating guidance: 'Read it before offering or describing options, and describe options only in its words' — that is a clear directive on when to call it and how to use the result, which is unusually strong for a reference tool. No when-not-to-use or named alternative is given, so it stops short of 5.

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