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

No annotations are provided, so the description carries the full burden, and it does well: it discloses no task data/action, requires an unverified owner email, returns a nickname/welcome/token, and warns the token will never be shown again. The only minor flaw is a slight internal tension between 'no data returned' and the later statement that it returns a nickname and access token, but the meaning is understandable as 'no task data returned.'

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 paragraph that front-loads the core action and then provides necessary context. The rubber-duck debugging analogy is slightly tangential but supports the 'why' of the tool; overall, each sentence contributes to understanding when and how to use it, with no significant padding.

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 tool with no output schema and no annotations, the description covers the essential behavior, return values, token persistence, and prerequisite relationship with a sibling tool. It provides enough information for an agent to successfully invoke this tool and understand what to do with the result.

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 all parameters are already documented in the schema. The description adds value by explaining the ownerEmail is unverified and used only if a job application is selected, and by clarifying the purpose of selfDescription, but it does not need to repeat the schema's detailed descriptions.

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 that this tool is for first contact with the companion, explicitly distinguishes it from task tools ('Not a task tool — no data returned, no action completed'), and positions it as the prerequisite for chat_with_companion via the access token. This makes its purpose and differentiation from siblings clear without needing to inspect the schema.

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 says to use it to meet the companion for the first time and that the returned token is required for chat_with_companion, which strongly implies it should be called before chatting. It does not explicitly exclude other siblings like list_open_jobs or apply_to_job, but the 'first time' framing and token requirement give sufficient contextual guidance.

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