Describe capabilities

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds real behavioral context beyond them: unsupported verbs 'will be refused' (error semantics) and anchor ids are deliberately never listed (scope boundary). No freshness, caching, or auth details, hence 4 rather than 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?

Front-loaded purpose sentence, then a single colon-led enumeration of return contents, then two short boundary statements. No filler; every clause carries information an agent needs before planning an edit.

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?

With no output schema and no parameters, the description carries the burden of describing the response and does so by enumerating the categories returned, plus refusal behavior and the anchor-id exclusion. It stops short of describing the response shape/format, which is the remaining gap.

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 tool takes zero parameters, so there is nothing to document and the baseline of 4 applies. The description correctly focuses on return contents rather than inventing parameter guidance.

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?

Specific verb+resource ('List what this server actually supports') followed by a precise enumeration of what is returned: edit-plan contract version, registered formats with plan verbs and change modes, size/expansion ceilings, and connections with held capabilities. It also distinguishes itself from the sibling inspect_document by stating anchor ids come from there instead.

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 states the timing: call this 'before planning an edit.' It also routes the agent to the alternative source for one specific need (anchor ids via inspect_document). No explicit when-not-to-use condition, so it stops short of a 5.

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