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

Annotations already establish the tool as read-only, idempotent, and non-destructive, and the description adds meaningful behavioral context: it returns paginated results (20 per page) and specifies the output fields. This goes beyond the annotations by clarifying the response structure and pagination behavior, though it doesn't cover rate limits or auth (likely not applicable).

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 a single, well-structured sentence that front-loads the core purpose ('Search Rick and Morty characters by name') and then efficiently packs in optional filters and return details. Every phrase adds value, with no redundant or filler content.

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 search tool with a rich schema and output schema, the description covers the essential aspects: the search target, optional filters, pagination limit, and returned fields. The schema fills in parameter specifics, so the description is complete enough on its own to guide correct invocation.

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 input schema provides 100% coverage with detailed descriptions for all five parameters, including defaults and partial-match behavior. The description reiterates the filter names (status, species, gender) but does not add new semantic meaning beyond what the schema already offers. The pagination detail ('20 per page') relates to output, not parameter semantics.

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 uses a specific verb ('Search') and resource ('Rick and Morty characters'), and clearly distinguishes from sibling tools like get_character (exact lookup) and search_episodes (episode search) by emphasizing name-based search with optional filters. It also outlines the returned data, leaving no ambiguity about the tool's function.

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 description provides clear context for when to use the tool: when searching characters by name or filtering by status, species, or gender. It does not explicitly mention exclusions or alternatives (e.g., using get_character for exact IDs), but the search-oriented wording implies this distinction. This is clear context but lacks explicit 'when-not' guidance.

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