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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive, closed-world), so the description only needs to add scope. It does add one useful note: only 'public' tools are returned and the canonical URL is included. Missing are behavior on unknown/non-public ids and error semantics.

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?

A single front-loaded sentence with zero filler. The key differentiator ('one ... by id') comes before the secondary detail (canonical URL).

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?

There is no output schema, so the description carries some burden for describing the response. It mentions one return field (canonical URL) but not the shape of the returned tool object, and the optional 'query' parameter is left entirely unexplained. Adequate but with clear gaps.

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% (both params described), so the baseline is 3. The description confirms the 'id' semantic ('by id') but says nothing about the optional 'query' object, leaving the agent with no idea what query parameters are accepted or useful.

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?

States a specific verb and resource: 'Return one public AffixIO tool by id'. The phrase 'one ... by id' distinguishes it from the sibling list/search tools (tools_catalogue, tools_search), though it never names them. Clear and unambiguous on its own.

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?

Usage is implied by 'by id' – you call it when you already have a tool identifier. There is no explicit when-to-use vs tools_search/tools_catalogue, no statement that it fails/404s for unknown or non-public ids, and no routing guidance for discovery workflows.

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