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

Annotations already declare readOnlyHint and idempotentHint, and the description complements this by specifying the return payload: 'A list of endpoints with their IDs, HTTP methods, paths, summaries, and deprecation status.' No side effects are claimed. It doesn't discuss error cases, but that's not expected for a read-only lookup.

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?

Structured with headings, no filler. Every section adds practical information—summary, use cases, parameter format, and return values.

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 single-parameter read-only tool, the description covers purpose, usage timing, alternatives, parameter format, and return shape. No output schema exists, but the return list description compensates.

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 only states tagId is required, but the description enriches it: 'The 32-character MD5 hash ID of the tag.' This gives the agent the exact format needed, exceeding schema baseline.

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 opens with a precise statement: 'Lists all endpoints grouped under a specific tag within a collection.' It also contrasts with tag_by_id, clarifying the tool's unique role among siblings.

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 'When to use' section explicitly lists scenarios (having a tag ID, user queries) and gives an alternative: 'To see the tag's metadata (title, method count) without listing endpoints, use tag_by_id instead.' This is model behavior.

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