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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful context beyond that by clarifying the search only covers approved public packs and explicitly excludes private generation requests, which is valuable behavioral scope not encoded in the annotations.

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 compact and front-loaded with the core action, followed by precise routing instructions. Every sentence earns its place with no redundancy or filler.

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 fully documented optional parameters and clear sibling routing, the description covers what the tool returns, when to use it, and when to avoid it. The lack of an output schema is acceptable because the tool's purpose is to discover matching pet packs, which the description conveys.

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 description coverage is 100%, so all six parameters are already documented. The description restates the filter dimensions (query, kind, tags, author, compatibility) but does not add new semantic detail beyond what the schema provides.

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 ('discover') with a clearly scoped resource ('approved public Codex pet packs') and enumerates the search dimensions. It explicitly contrasts itself with get_pet, making the tool's distinct role immediately clear.

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 gives explicit when-to-use guidance: prefer when no exact slug or when multiple candidates are needed. It also states what not to use it for and names the correct alternatives, get_pet_request_info and slug-specific get_* tools.

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