intercom_whoami

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

No annotations are provided, so the description carries the full burden. It conveys a read-only intent but does not disclose the structure of the identity, potential errors, or any prerequisites. The description is minimal and adds little beyond the tool name.

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 a single, front-loaded sentence with no unnecessary words. It directly states what the tool does and adds a brief purpose ('for reliable targeting'), earning the highest score for conciseness.

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, no-output-schema tool, the description is largely complete: it explains the purpose and use case. However, it could be slightly richer by indicating the nature of the returned identity (e.g., ID, email, role), which would aid an agent in using the result. This minor gap justifies a 4 rather than a 5.

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, so the baseline is 4. The description appropriately focuses on the output (identity) and does not need to explain parameter semantics. No additional meaning is required beyond what the empty input schema conveys.

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 states the tool's function with a specific verb ('Return') and resource ('this Codex session's intercom identity'). It is distinct from sibling tools like intercom_team or intercom_status, as it focuses on the caller's own identity.

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 phrase 'for reliable targeting' provides clear context for when to use the tool (to obtain the caller's identity for targeting), but it does not explicitly exclude or contrast with alternative tools. This is clear context without exclusions, matching a score of 4.

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