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

Annotations already mark the tool as mutating and destructive, so the description's main job is to add behavioral nuance. It does: archiving does not delete rows, it only removes the category from pickers. This is valuable context beyond what readOnlyHint, destructiveHint, or idempotentHint provide.

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, efficient sentence with a parenthetical for the most surprising behavior. It is front-loaded with the primary actions and contains no filler or repetition of schema or annotation details.

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 update tool with an output schema and destructive/readOnly annotations, the description covers the main behavioral nuance an agent needs. It could be more complete by mentioning the required id or listing sibling alternatives, but the remaining gaps are minor given the low parameter complexity.

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 description coverage is 0%, so the description must compensate for parameter meaning. It maps operations to parameters: 'Rename' suggests name, 'change its icon' maps to icon, and 'archive it' maps to archived. However, the required id parameter is not explained, and icon/name formats are unspecified, leaving semantic gaps.

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 specific verb-resource pair ('Rename a category') and enumerates the exact operations available: rename, change icon, archive. It also clarifies the subtle archiving behavior (rows keep their category; it just leaves pickers), which clearly distinguishes this tool from add_category or delete-related 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 description makes the intended use clear: use this tool when a category needs renaming, icon changes, or archiving. It also explains the consequence of archiving, which helps an agent decide correctly. However, it does not explicitly name alternatives or state when not to use this tool versus add_category or set_category_rule.

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