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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the safety profile is covered; the description adds genuinely new context by disclosing that delivery history is destroyed along with the endpoint and that the receiving system loses events silently, with no other warning.

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?

Two tight sentences, front-loaded with the 'Destructive:' signal, and every clause earns its place by adding scope or consequence rather than restating the title.

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 single-parameter delete with full annotation coverage and no output schema, the description covers what is deleted, the collateral loss of history, and the external effect. Only minor gaps remain, such as whether the deletion is immediate/permanent or requires any confirmation.

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 single webhook_id parameter is fully documented there (including its provenance from list_webhooks), so the description adds nothing on parameters; the baseline of 3 applies when the schema carries the full burden.

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 ('Delete a webhook endpoint') and goes further by naming the collateral object ('its delivery history'), which cleanly separates it from sibling mutations like update_webhook, delete_block, and delete_project.

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?

Usage is only implied: the consequence clause ('The receiving system stops getting events') suggests when an agent would want this, but there is no explicit when-to-use, no when-not-to, and no pointer to alternatives such as update_webhook or rotating the secret instead.

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