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

Beyond the annotations (destructive, idempotent, not read-only), the description discloses that auth is required, what the response contains ('the list entry with deleted true'), the specific failure modes and codes (400 invalid_list, 400 invalid_entry, 404 list_entry_not_found, inbox_not_found), and a non-obvious side-effect boundary regarding the per-inbox task allowlist.

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?

The usage condition is front-loaded, then deletion semantics, inputs, return, and errors in a tight sequence. No filler sentences; every clause carries operational information.

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 no output schema, the description compensates by stating the return shape ('deleted true') and the error surface. For a one-entity destructive delete, an agent has everything needed to call it correctly and interpret the result.

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%, so the schema already documents all four parameters including enums. The description restates the same required/optional split and the 'omit for the account-wide list' nuance the schema already carries, adding no meaning beyond it. 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 ('Deletes that one entry') and resource (allow or block list entry), and the leading sentence frames the exact situation that triggers it. It is clearly separable from siblings cooper_create_list_entry, cooper_get_list_entry, and cooper_list_list_entries.

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 opening clause gives an explicit when-to-use condition ('when an address or domain should leave an allow or block list'), and the closing note scopes the effect ('The per-inbox task allowlist is unchanged'). It does not, however, name the sibling alternative for adding an entry, so routing is implied rather than stated.

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