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

Annotations already declare readOnlyHint and idempotentHint, covering safety. The description adds context about the hierarchical navigation pattern and discloses the return format (list of tags with IDs, titles, method counts), providing value beyond structured data.

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 well-organized with clear headings (overview, when to use, parameters, returns), is appropriately sized for a simple tool, and contains no redundant or filler language.

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 tool with one parameter and no output schema, this description fully covers purpose, usage, parameter semantics, and return shape. The sibling-tool context and annotations further round out the operational picture, leaving no critical gaps.

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?

While schema coverage is 100%, the schema's description is merely 'required,' which provides no real meaning. The tool description compensates by explaining that collectionId is a '32-character MD5 hash ID of the collection,' offering actionable semantic detail beyond the schema.

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 'Lists all tags within a specific collection,' which is a specific verb+resource+scope statement. It explicitly distinguishes from the sibling tool tag_by_spec by noting the collection-level scope versus spec-wide scope.

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 includes a dedicated 'When to use' section with concrete scenarios (having a collection ID, hierarchical navigation, user queries) and explicitly directs users to tag_by_spec for the alternative case, satisfying both when and when-not guidance.

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