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

Goes well beyond the readOnlyHint=false annotation: it discloses the provenance fields written (sent_by, agent_id, task_id) onto the record and audit trail, the auth mechanism (hub-claim JWT requiring MOSADD_API_KEY, verified with HUB_JWT_SECRET), and that body trust is never granted for provenance. The implementation-facing jargon is noise but the behavioral disclosure is unusually rich for a mutation tool.

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?

Front-loaded with the core distinction and the provenance effect, then auth. Mostly earning its place, though the naming of the internal 'mp0st-send EF' and env-var secrets is implementation detail that costs a sentence without helping tool selection.

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 10-parameter mutation with no output schema and minimal annotations, the description covers identity/provenance and auth well but omits delivery behavior, return shape, failure modes, and most parameter meanings. An agent knows why to call it, but not fully what to expect back.

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 only 20% (10 params, only task_id and agent_id documented), so the description must compensate. It does clarify what agent_id and task_id become on the record (sent_by_agent_id, sent_by_task_id), but says nothing about tracking, reply_to, or the body_html vs body_text choice, leaving most parameters undocumented.

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?

Specific verb + resource ('Send an email') with a precise qualifier: the send is attributed to the agent and provenance-stamped. It explicitly contrasts with the sibling mAYL_send ('sends as the user'), so an agent can distinguish the two without opening either 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 contrast with mAYL_send establishes the selection condition: use this when the mail must be visibly agent-originated for recipients/compliance. It does not spell out a 'do not use when' case or mention rate limits, but the routing signal to the alternative tool is clear.

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