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. Beyond that, the description adds real value by seeding the concrete stage identifiers (MAIN, SHEET, FACE, BIOMETRIC, LOOKS, OUTFITS, POSES, PROFILE, LOCATIONS) that a caller will need to pass elsewhere, plus the breadth of categories returned. It stops short of describing the response shape (keyed object vs. arrays).

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?

A single front-loaded sentence with the '[read]' tag first and the resource stated immediately. The list is long but each element is a distinct option family, so little is wasted; a slightly tighter grouping would improve it.

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 input schema and no output schema, the description carries the burden of explaining what comes back, and it does so by enumerating the option families and stage constants. What is missing is the response structure (how categories map to keys) and any note on caching/staleness or size, which would make it fully self-sufficient.

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?

The tool takes zero parameters, so the baseline is 4. The description's enumeration describes the returned option domains rather than inputs, which is appropriate for a no-arg catalog call.

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 description clearly identifies the resource: the catalog of option values for the character form, enumerating styles, purposes, types, colours, body types, output formats, stages, providers and suggestions. It is specific about content but never names a sibling (e.g. create_character, get_character, list_characters) to distinguish when to fetch options versus fetch a character.

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?

Usage is only implied: an agent can infer this is a discovery/enumeration call that precedes create_character or edit_character, but the description never states that, nor does it list any preconditions or exclusions. No alternative tool is mentioned.

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