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

Annotations already cover read-only, idempotent, and non-destructive behavior, so the description's added return-shape detail is valuable: a full catalog array of hashes with named keys. It does not mention possible Ruby execution errors or large-result considerations, but these are not critical given the annotation coverage.

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 front-loaded with purpose and usage, and every section is relevant. The example block is dense and runs as one long line, so splitting it into a scannable bullet list would improve structure without losing information.

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?

Because there is no output schema, the description takes on the responsibility of describing the return value, and it does so by listing the hash keys and showing multiple example expressions. The annotations, input schema, and sibling context together make this description complete enough for an agent to use the tool correctly.

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 documents the `code` parameter at 100%, but the description goes further by giving three concrete Ruby-level examples that show filtering by tag, finding a specific request body, and listing domains. This provides practical meaning beyond the schema's single descriptive sentence.

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 a concrete verb and resource: 'Discover available Crevio API endpoints.' It also names the sibling `api_execute` and positions `api_search` as the discovery/exploration tool, which distinguishes it from the other sibling tools without needing to open their schemas.

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 explicitly says to use this BEFORE `api_execute` when unsure of the endpoint, parameter names, or domain details, which is a strong positive usage rule. However, it does not state the negative case explicitly, such as 'if you already know the exact endpoint, call api_execute directly'.

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