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

With no annotations, the description carries the full behavioral burden and fails it. It does not say whether 'compose' creates a draft or sends immediately, whether authentication is required, or whether the action is reversible — critical ambiguity for a mail-writing tool.

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?

It is a single short sentence, but 'Run Google mail action:' is filler prefix that consumes space without conveying information. The useful content ('compose email') is present but minimal.

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 mail-mutating tool with no annotations, no output schema, and an ambiguous generic parameter, the description leaves the agent without enough to call it correctly or predict its effect.

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 single 'detail' parameter is already documented as 'Task-specific details from the objective.' Per the baseline rule, 3 is appropriate when the schema does the heavy lifting and the description adds nothing further.

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 phrase 'compose email' names a verb and resource, but 'Run Google mail action:' is generic wrapper boilerplate that adds no discriminating detail. An agent can infer this differs from the read-oriented siblings (latest_emails, read_single_email), but the description never states it 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?

There is no guidance on when to use this tool versus the sibling converse or read_single_email, and no prerequisites or context are given. Usage must be entirely inferred from the name.

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