Show fmsg identity

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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond this: the address is derived from the API key and the access token renews automatically with no action needed. This preemptively addresses a common concern about authentication and expiry, which is genuinely useful.

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 description is two sentences with no filler. The first sentence front-loads the tool's output and its four concrete reports; the second provides a clear usage tip. Every clause earns its place, and the structure is easy to parse for an agent.

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, non-destructive identity-reporting tool with an output schema, the description covers everything necessary: what is reported, how the address is derived, token renewal behavior, and when to call it. There are no missing prerequisites, side effects, or tricky behaviors that an agent would need to know.

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 has zero parameters and schema coverage is 100%, so there is nothing for the description to explain about inputs. The baseline of 4 applies here because no parameter documentation is needed, and the description correctly focuses on the output semantics instead.

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 identifies the tool's purpose with a specific verb ('Report') and a concrete resource (the fmsg identity), listing exactly what is reported: address, API URL, token expiry, and resolution defaults. It stands apart from siblings like send_message or list_messages by focusing on identity rather than messaging 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?

The description gives an explicit usage trigger ('Call this first if unsure who you are sending as'), which tells the agent when the tool is appropriate. However, it does not explicitly discuss when not to use it or name alternatives, though no direct sibling serves the identity-checking role.

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