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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is partly covered; the description adds real value beyond them by stating the deletion is permanent, that Spur defaults are protected, and that user confirmation is a required step. It does not say what happens to campaigns or letters already using the template, which is the main remaining unknown for a destructive call.

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?

Three short sentences, each doing distinct work: what it does, what it can't touch, and the required confirmation step. The permanence warning is front-loaded and there is no filler.

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 two-parameter destructive tool with full schema coverage and rich annotations, nothing essential is missing: permanence, the default-template restriction, and the confirmation workflow are all stated. No output schema exists, so no return-value explanation is owed.

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% and the confirm parameter's description already carries the strong 'only after explicit approval' wording, so the description cannot add much. It does implicitly reinforce the confirm gate with 'Confirm with the user first,' but adds no format or sourcing detail for template_id beyond what the schema states. Baseline 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 ('Permanently delete') and a precisely scoped resource ('one of the user's letter templates'), which cleanly separates it from the sibling delete tools for message, postcard, QR code, and image resources. It also adds a hard scope boundary: 'Spur defaults can't be deleted.'

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 precondition ('Confirm with the user first') and an exclusion (Spur defaults), which is more than most delete tools offer. It stops short of naming alternatives — e.g., that spur_update_letter_template should be used for edits rather than delete-and-recreate — so it isn't a full routing statement.

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