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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds a genuine behavioral constraint in 'you can see in your firm's synced mailboxes', implying access scoping, but says nothing about what happens for a message outside that scope or for an unknown id.

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?

A single front-loaded sentence that enumerates the returned analysis fields efficiently. The field list is slightly long but each item tells the agent what to expect, so it 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?

With an output schema and full read-only annotations, the return values and safety profile are already covered. The gap is parameter guidance: for a tool requiring a message id and an optional firm id, leaving both undocumented makes the definition only adequate, not 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?

Schema description coverage is 0% for both parameters, so the description carries the full burden — and it never mentions message_id or firm_id. The phrase 'your firm's' hints that firm scoping is applied, but neither the id format nor the role/default of firm_id is clarified.

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 ('Get one email') plus the payload it returns (full text and AI analysis fields). The singular framing implicitly separates it from the sibling list tool get_email_messages, but that contrast is never stated explicitly.

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: 'one email ... with its full text and AI analysis' suggests calling it after locating a message id via get_email_messages, but no when-to-use, prerequisites, or alternative is named. An agent must infer the workflow.

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