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

Annotations already declare destructiveHint, idempotentHint and readOnlyHint=false, so safety is covered. The description adds genuinely non-obvious behavior beyond that: an already-emailed domain remains uncontactable and only its subdomains are unblocked, plus a 100-per-call batch limit. It does not state error behavior for non-blocklisted domains.

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, the core action front-loaded, and each clause carries distinct information (source of text, side-effect caveat, batch limit). 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 simple two-parameter mutation with no output schema and annotations covering the safety profile, the description supplies the caveat, the input format requirement and the batch cap. Only failure/partial-application behavior is left unstated.

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 baseline is 3, but the description adds constraints the schema does not: domains must be passed as the exact text list_blocklist returns, and at most 100 may be submitted per call. That meaningfully constrains the domains array beyond its schema entry.

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?

Specific verb (remove) plus resource (domains from the blocklist), and it is immediately distinguishable from the sibling block_domains. An agent knows exactly what this does without opening a schema.

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?

It routes the agent to list_blocklist as the source of the exact domain text and explains the relevant conditional case (an already-emailed domain stays uncontactable). There is no explicit when-not-to-use statement, but the operational context is clear.

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