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

Beyond the minimal annotations, the description discloses the wholesale replace behavior, that an empty/omitted description clears it, that slug cannot be changed, and that display_name is required. This is exactly the behavioral nuance an agent needs before invoking a mutation.

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 with no fluff; the scope and key constraint (metadata only) appear first, followed by the critical wholesale-replace caveat and the safe usage pattern. 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 mutation tool with two required parameters and a clear output schema, this description fully covers what changes, what does not change, what cannot change, and the safe sequence to follow. Nothing an agent needs to call it correctly is missing.

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 all parameters, so baseline is 3. The description adds extra meaning beyond the schema by explaining that display_name is required, description is set wholesale, omitting description clears it, and both should be passed to avoid losing values.

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?

Description uses a specific verb ('Update') with a specific resource ('api template') and identifies exactly which fields are affected (display_name and description). It also clearly distinguishes itself from create_api_template_version by noting this does not change the request definition.

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?

Description explicitly states this is metadata-only and directs authoring request definitions to create_api_template_version. It also tells the agent to read current values with get_api_template first when changing only one field, giving a concrete usage procedure.

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