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

With no annotations provided, the description carries the full burden and discloses key behavioral traits: the operation is 'Free and read-only; spends nothing' and only returns settlement-verified listings unless told otherwise. This is valuable context beyond the schema. It doesn't mention pagination or rate limits, but the essential safety and filtering behavior is covered.

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?

Three concise sentences, front-loaded with the core purpose. Every sentence adds information: browse behavior, category handling, verified filtering, and cost/safety. There is no filler or redundancy.

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 simple listing tool with three optional parameters and no output schema, the description covers the main usage, filter semantics, and side-effect profile. Missing guidance is limited to sibling routing and pagination details, and those are partially implied by the schema constraints.

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 low (33%), and the description compensates for category and verified_only: it defines the category filter ('Omit category for everything') and the verified_only default behavior. However, the 'limit' parameter is never described in either the schema or the description, leaving a small but real gap.

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 states the operation: browsing/listing the live catalogue, optionally filtered by category. It uses a specific verb and resource. It distinguishes itself from get_api and search_apis by the notion of browsing the full catalogue, though it does not name the siblings explicitly.

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 direct usage guidance: 'Omit category for everything' tells when to skip the filter, and 'Returns settlement-verified listings only unless verified_only is false' explains the default behavior. It also notes the tool is free and read-only, signaling safe use. It doesn't explicitly say when to prefer search_apis or get_api, but the context is clear.

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