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

Annotations only declare the generic profile (readOnly=false, destructive=false, idempotent=false); the description adds the non-obvious cascade that the component's file is renamed and every {% render %} reference is rewritten. That is exactly the extra context annotations cannot convey. It does not say what happens on a name collision or whether the rewrite is atomic, keeping it below 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?

A single sentence with the scope qualifier front-loaded and the side effect appended as a consequence clause. Nothing is wasted and nothing important is buried.

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 three-parameter mutation with no output schema, the description covers the main risk (cascading reference rewrites) but leaves out collision/validation behavior, whether the old name remains valid, and permission requirements. Adequate to call correctly, not complete for a non-idempotent mutation.

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 coverage is 67%: 'component' is documented as coming from list_components, but 'name' has no schema description at all. The description says 'rename' without stating that name is the new component name, and says nothing about the optional 'id' site identifier. Baseline 3 is warranted, with a small gap left by the undocumented name parameter.

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 names a specific verb and resource (rename a component) and immediately scopes it to HTML-first sites, which separates it from generic file-edit siblings like edit_site_file. It stops short of naming delete_component or list_components as adjacent operations, but the action itself is unambiguous.

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 'HTML-first sites:' prefix implies a precondition (this applies only to HTML-first sites) but is never expanded into an explicit when-to-use or when-not statement. An agent must infer that non-HTML-first sites should use a different mechanism, and no alternative tool is named.

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