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

Goes well beyond annotations by disclosing that the previous name is overwritten, that the id and signatures are preserved, that the folders:write scope is required, and that unknown ids return 404 while blank names return 422. All of this is consistent with destructiveHint=true and idempotentHint=true (overwrite is idempotent) – no contradiction.

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?

Front-loads the core action and scope, then packs routing guidance and error/auth behavior into two dense but waste-free sentences. Nothing is repeated from the schema for its own sake.

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 mutation tool this is thorough: it covers what changes, what is preserved, required scope, error conditions, and alternatives. Since an output schema exists, the brief mention of signature_count in the return is a bonus rather than a required detail.

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%, so all three parameters are already documented in the schema, which sets the baseline at 3. The description reinforces the UUID identifier ('by UUID', matching list_folders output) and the overwrite semantics of name, but adds no syntax or format 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?

States a specific verb (rename) and resource (signature folder), and clarifies scope by declaring the name is the only mutable property. It also distinguishes itself from create_folder/delete_folder, so an agent can identify it without opening the schema.

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?

Explicit routing: 'prefer this over create_folder plus delete_folder when only the name is wrong', 'to move a signature ... use update_signature with folder_id', 'to remove the folder, use delete_folder'. Both when-to-use and when-not-to-use with named alternatives are present.

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