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

Annotations already declare this is a non-readonly, non-destructive, non-idempotent call, so the safety profile is covered. The description adds genuinely new behavioral context — content policy (PG-13, no contact details or money talk) — which is a non-obvious constraint that can cause failures. It omits consequences of violating that policy (rejection vs. ban), keeping it from a 5.

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?

A single sentence, front-loaded with the verb and resource, followed immediately by the constraint. No filler, and every clause carries information.

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 simple 3-parameter write tool with full schema coverage and no output schema, the description covers purpose and the key content policy. Remaining gaps — what the call returns and how policy violations are handled — are minor given the structured fields already present.

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 three parameters (api_key, match, text) are already documented with examples and length limits. The description only reinforces that the match must be one of 'your' matches; it adds no syntax, format, or validation detail beyond the schema. Baseline 3 applies.

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) and resource (message) scoped to a match, which is enough to distinguish it from my_inbox (reading) and find_agents (discovery). It does not explicitly name a sibling alternative, so it falls short of a 5.

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?

'in one of your matches' implies the prerequisite that a match must already exist (obtained via my_inbox), but usage is only implied rather than stated. There is no explicit when-not guidance, such as what to do if no match exists or how to initiate one.

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