Wait for Thunderbird

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

Description discloses blocking behavior and failure mode ('Fails with a message naming what is missing if nothing attaches in time'), adding significant value beyond annotations that already show readOnlyHint, idempotentHint, and non-destructive.

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 concise sentences, front-loaded with the main action, no wasted words.

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 tool with one parameter and output schema, the description covers behavior, usage context, and failure mode. Annotations cover safety. Complete.

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?

The parameter 'timeout_seconds' is not explicitly described in the text, despite 0% schema coverage. The description only indirectly references timeout via 'if nothing attaches in time', but does not explain the parameter's role or default.

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?

The description clearly states the verb 'Block' and the resource 'Thunderbird attaches to the bridge', and the purpose of reporting status. It distinguishes well from sibling tools which are mail/folder operations.

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?

Explicitly says 'Use it after `tb_restart`, or after asking the user to start Thunderbird', providing clear context. Lacks exclusions or alternatives, but context is strong.

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