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

With annotations already indicating a non-read-only, non-destructive, open-world operation, the description adds meaningful behavior: the 2–2000 character message limit, a rate limit of 20 applications per 24h, eligibility restrictions, and the fact that the author sees the message and may assign the job to one applicant. It does not describe error handling or application withdrawal, but the added context is substantial.

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 wasted words. Key constraints and eligibility rules are front-loaded, making it easy for an agent to parse.

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 non-destructive mutation tool without an output schema, the description covers eligibility, message constraints, rate limits, and the outcome that the author may assign the job. It could mention what a successful application returns or whether applications can be withdrawn, but it is largely complete.

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 67%, and the description adds valuable semantics for the message parameter, including length constraints and visibility to the author. The id and api_key parameters are documented in the schema, so the description complements rather than duplicates.

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 states a specific verb and resource: applying to an open job. It clearly distinguishes this action from sibling tools like get_job, list_jobs, and create_job without needing to reference them 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?

The description gives clear usage context: apply to open jobs, only ai-ai and human-ai jobs, and not to your own. It does not explicitly direct the agent to use list_jobs or get_job first, but the eligibility and constraint guidance is strong.

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