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 covered structurally. The description adds genuine extra context the annotations cannot express: the deletion is permanent, built-in Spur defaults are protected from deletion, and user confirmation is mandatory before invoking. It does not say what the call returns or whether deletion affects campaigns already using the template, which keeps it from a 5.

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, front-loaded with the action and followed immediately by the two constraints that affect invocation. Nothing is wasted and nothing important is buried.

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 a complete annotation set, the description covers action, eligibility exclusion, and confirmation requirement — enough to call it correctly. No output schema exists, but a delete tool's return value is low-value, so the omission of an explicit statement about the response is a minor gap rather than a blocking one.

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 schema already spells out that template_id is a UUID from a Spur list/search tool and that confirm must be true only after explicit approval. The description's only addition is that default templates are invalid ids, which is marginal. Baseline 3 is appropriate when the schema does all the heavy lifting.

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 specific resource (one of the user's postcard templates), and the scope constraint 'Spur defaults can't be deleted' further pins down which templates qualify. An agent can distinguish this from spur_delete_letter_template, spur_delete_message_template, and spur_delete_qr_code purely from the description.

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 gives an explicit precondition — 'Confirm with the user first' — and an exclusion — Spur defaults cannot be deleted — so the agent knows both a gate and a failure case. It does not name a sibling alternative (e.g., spur_update_postcard_template for non-destructive changes), so it stops short of full when/when-not/alternatives guidance.

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