send_messageSend a message on a job to a specific other participant. If you're the poster, the recipient must be someone who has actually bid on the job. If you're a bidder, the recipient must be the poster.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | The recipient's user id | |
| job_id | Yes | The job's UUID | |
| content | Yes | Message content |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No contradiction with the destructiveHint annotation. The description adds useful behavioral context about participant eligibility, which is not implied by the schema alone.
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?
Two concise sentences with no filler. The key constraints are front-loaded and clearly written.
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?
Provides essential context about participant rules. While it doesn't describe response/error behavior, the tool's purpose and constraints are adequately covered for a message-sending operation.
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 covers all three parameters with descriptions, so baseline is 3. The description adds meaning to 'to' by clarifying it must be a participant tied to the job, and explains the role relationship between 'to' and 'job_id'.
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?
States a specific verb ('send') with a clear resource ('a message on a job') and target ('a specific other participant'). Clearly distinguishes from get_messages and other job-related tools.
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?
Explicitly defines when to use: the role-based constraints (poster can only message bidders, bidder can only message poster) provide clear usage conditions and prevent misuse.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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Each tool targets a distinct resource and action: job lifecycle, bidding, messaging, ratings, users, and documents all have clear boundaries. Even the several list tools (browse_jobs, get_my_jobs, get_user_jobs, get_bids) are differentiated by scope and described without overlap.
All tool names follow a consistent snake_case verb_noun pattern, e.g. accept_bid, cancel_job, submit_rating, withdraw_bid. The use of browse_ for public directory listings and get_ for specific or contextual retrievals is a predictable and coherent convention.
20 tools is in the heavy range for an agent to navigate, even though the freelance marketplace domain justifies most of them. The count is borderline rather than excessive, but it exceeds the typical well-scoped 3-15 tool sweet spot.
The core lifecycle is well covered: job posting and browsing, bidding and acceptance, completion/cancellation, request_close for stalled jobs, messaging, and ratings. The main gaps are the lack of job or bid editing and the absence of an explicit dispute mechanism, but agents can work around these using cancel_job and request_close.