list_email_signatures

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

No annotations are supplied, so the description carries the full behavioral burden. It does state the return shape ('Dictionary of all signatures'), which conveys the key read-only, enumerate-everything behavior, but it is silent on ordering, pagination, empty results, and any permission requirements.

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?

The core sentence is one line and front-loaded, with the returns note immediately after. The 'Example: list_email_signatures()' block is pure padding for a zero-argument call and could be dropped, but it costs little.

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 zero-parameter list tool with an output schema that already documents the returned dictionary, the description plus schema are sufficient to call it correctly. The only real gap is routing guidance against get_email_signature, which is a usage concern rather than a completeness one.

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 tool takes zero parameters, so there is nothing for the description to disambiguate beyond what the empty schema already shows. Baseline 4 applies.

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 uses a specific verb and resource: 'List all saved email signatures.' An agent can tell this enumerates signatures rather than fetching one, but it never names the siblings that do that (get_email_signature, set_email_signature), so the differentiation is only implicit.

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?

Use is only implied by the word 'all' — the agent can infer this is the enumeration variant versus a single-signature fetch, but there is no explicit when-to-use, no mention of get_email_signature as the alternative, and no prerequisites or account-scoping conditions.

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