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

Annotations already declare the mutation and destructiveHint=true profile, and the description adds real behavioral context beyond that: only style and scale are editable, party reassignment is impossible, and discovery requires get-template-info. It does not, however, say whether the update is reversible or what the response contains, which is the remaining gap.

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-loaded one-line purpose, then a scannable when-to-use bullet, then hard constraints. Four short units, each carrying an operational fact; nothing is padding.

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?

With an output schema present the description needn't explain return values, and it covers purpose, constraints, and the prerequisite lookup. Nothing an agent needs in order to call this correctly is missing.

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 the schema carries the parameter documentation (baseline 3). The description adds genuine meaning beyond the schema by stating that the party association is immutable and that style/scale are the only mutable properties, plus it repeats the discovery path for signature_block_uuid.

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 and resource ('Update the presentation of a signature block on a template') and scopes it to presentation only, which cleanly separates it from create-template-signature-block and delete-template-signature-block among the 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?

Gives an explicit when-to-use condition ('the user wants to change how an existing signature block looks'), names the two mutable fields, and states the workaround for the excluded case (delete and recreate to move a party). It also points at get-template-info as the discovery step, so the agent knows what to do before calling.

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