update_label

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds only the "(folder)" gloss and says nothing about side effects such as the new name propagating to all messages/threads already carrying the label, and nothing about the response.

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 short sentence with the key information front-loaded and zero waste. It is arguably too terse for a rename operation, but nothing is redundant.

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?

A simple two-parameter mutation whose annotations and schema carry most of the load, so the description is close to sufficient. It nonetheless omits the propagation effect of a rename and any indication of the response, which a caller would want for a mutating tool with no output schema.

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 100%, with both labelId ("User label id from list_labels") and displayName ("New name") documented. The description adds no meaning beyond that, so the baseline of 3 applies.

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?

States a specific verb (renames) and resource (user label), and the parenthetical "(folder)" clarifies what a label is in this API's vocabulary. It does not explicitly distinguish itself from create_label/delete_label/list_labels, but the verb makes the distinction reasonably evident.

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?

No guidance on when to use this versus create_label or delete_label, nor any prerequisites (e.g., that the label must already exist). The only routing hint, that labelId comes from list_labels, lives in the schema rather than the description.

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