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

With readOnlyHint=true, the safe read nature is already covered by annotations. The description adds behavioral detail beyond that: it returns all API paths along with HTTP methods and summaries, organizes results by path, and emits output suitable for chaining into get-endpoint. This is useful context not present in the annotations.

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?

The description is two sentences with no filler. The first sentence states the core action and output, and the second adds a valuable composition hint. Every sentence earns its place and the essential information is front-loaded.

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 simple, parameterless listing tool, the description fully covers what is returned, how results are organized, and how they can be used next. The readOnlyHint annotation handles side-effect transparency, and no output schema is necessary given the clear description of the result contents.

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 has zero parameters, so the schema and annotations already fully define invocation requirements. The description adds no parameter-level semantics, but none are needed; the baseline of 4 for parameterless tools is appropriate.

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 begins with a specific verb and resource: 'Lists all API paths and their HTTP methods with summaries.' It clearly defines the tool's scope as enumerating endpoints rather than executing or fetching one, which differentiates it from the sibling tools get-endpoint and execute-request.

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 description implies a workflow by noting that results can be passed directly into 'get-endpoint', which gives some usage context. However, it does not explicitly say when to choose list-endpoints over search-endpoints or when not to use it, so the guidance is implied rather than stated.

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