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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive. The description adds genuinely useful behavior beyond them: the version-resolution rule (published if any, else latest) and the fact that the definition body is included. It doesn't cover error behavior for a missing slug/id, keeping it below a 5.

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?

Two sentences, zero waste, with the scoping/return rule front-loaded ahead of the sibling redirect. Every clause earns its place.

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 read-only lookup with an output schema, the description covers what an agent needs: what is fetched, how the version is chosen, and where to go for other versions. Return-value detail is correctly left to the output schema.

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% and both parameters already document the 'provide this or slug' either/or constraint. The prose restates 'by slug or id' without adding format or precedence guidance, so the schema carries the load — baseline 3.

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 ('Get a single api template') and specifies the lookup keys (slug or id). It also defines what is returned ('the definition body of its current version'), which cleanly distinguishes it from get_api_template_version and list_api_templates.

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?

Explicitly names the alternative tool and the condition that selects it: 'Use get_api_template_version to read a specific older version.' An agent can route between the two without inference.

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