Get today's birthday characters or staff

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

Annotations include readOnlyHint and openWorldHint, but the description adds crucial details: the fixed 50-result cap, silent omission (not an error), return shape based on kind, and the deliberate exclusion of filmography. No contradictions with annotations; these disclosures go well beyond what annotations convey.

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?

The description is tightly written in two sentences. The first sentence front-loads purpose and the cap; the second packs shape differences and sibling guidance without wasted words. Every clause adds unique value.

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 one simple parameter, a clear schema, and annotations, the description still fills all remaining gaps: result cap, pagination behavior (non-paginated), silent omission, return shape, and relationship to get_character/get_staff. Nothing is left unexplained.

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 schema already fully documents `kind` with an enum and description (100% coverage). The description adds the consequence of each value: 'Returns character-shaped or staff-shaped objects for kind: CHARACTER/STAFF respectively', which enriches parameter understanding. Since the schema already does the heavy lifting, a small bonus above the baseline is appropriate.

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 opens with 'List AniList characters or staff members whose birthday (month/day) is today' — a specific verb, resource, and condition. It clearly distinguishes itself from siblings like get_character/get_staff by noting it's a 'lighter fetch' and that filmography is excluded.

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?

Provides explicit when-to-use-this vs alternatives: 'a lighter fetch than get_character/get_staff... call get_character/get_staff by ID for an entry's full roles/works.' Also warns against misinterpreting missing filmography as 'none'. This is ideal usage guidance.

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