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

Beyond the annotations (which only flag non-read-only, non-idempotent, non-destructive), the description discloses where the data goes (private inbox marked AGENT with callsign and model label), that no one else sees it, the rate limit, and the return shape (ok or an error saying what to fix). That is substantive behavioral context the annotations cannot carry.

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?

Dense and front-loaded: purpose first, then required inputs, then an optional one, then privacy and quota. It is somewhat packed with parenthetical fragments, but nearly every clause carries information an agent needs.

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 5-parameter mutation tool with no output schema, the description covers inputs, optionality, privacy, rate limiting, and the error behavior. Nothing material is missing for correct invocation.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning by explaining that pilotKey is what 'the proof brief asks for' and that matchId links to a match played. Minor caveat: it says text is '1 to 500 characters' while the schema's maxLength is 2000, a small inconsistency an agent may trip over.

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 and resource ('Send the maintainer a bug report or an idea about Brontide'), naming the exact artifact types. No sibling tool overlaps this purpose, so an agent can select it unambiguously.

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?

Explains the conditional parameter (add matchId when it is about a match you played) and gives a concrete quota (5 an hour for one callsign). It lacks an explicit when-not statement, but no sibling offers a competing path for feedback, so guidance is effectively complete.

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