Rename a tag

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

Annotations already declare idempotentHint=true. The description adds meaningful behavioral context: 'every link carrying it keeps it' and details the failure condition for duplicate names. No annotation contradiction present.

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 extremely concise with two sentences. The first sentence states the action and effect, and the second adds the constraint and alternative. Every sentence serves a clear purpose and 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 two-parameter tool with no output schema, the description covers the purpose, side effects (link preservation), failure mode, and alternative tool. It is fully sufficient for correct agent behavior.

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 coverage is 100% with both parameters having descriptions in the input schema. The description does not add additional meaning to the parameters beyond what the schema already provides, so a baseline of 3 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 clearly states 'Renames a tag' with a specific verb and resource. It distinguishes itself from sibling tools like merge_tags by explicitly explaining the uniqueness constraint and pointing to merge_tags for folding tags instead of renaming.

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 provides explicit guidance on when not to use the tool (when the new name already exists, which causes failure) and directly names the alternative: 'use merge_tags to fold two tags into one instead'. This is clear context for agent decision-making.

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