mail_read

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

No annotations are provided, so the description carries the behavioral burden. 'Read' implies a non-mutating operation, so the safety profile is inferable, but the description says nothing about error behavior for invalid/stale paths, authentication, or whether attachments and HTML are included in 'full content.'

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 short sentences with zero filler; the purpose is front-loaded and the prerequisite follows immediately. Every sentence earns its place.

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, read-only tool with no annotations or output schema, the description covers what it does and where the argument comes from. It could be slightly richer about what 'full content' includes (body, attachments, headers), but nothing essential for correct invocation is missing.

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% and the single parameter is self-describing, so the baseline would be 3. The description adds real value by naming mail_recent as an additional valid source for file_path, while the schema mentions only mail_search.

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: 'Read full email content,' which is clearly distinct from search/list operations. It names the tools that produce its input (mail_search, mail_recent), giving implicit differentiation, but does not contrast against the closely-related siblings mail_thread or messages_conversation that also surface message bodies.

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?

Gives a clear chaining instruction — use the file_path from mail_search or mail_recent results — so the agent knows the prerequisite and the workflow position. There is no explicit 'do not use this for X' statement and no guidance on when to prefer mail_thread instead.

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