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

The description adds significant behavioral detail beyond annotations: it states that the answer is 'public at once and not removable by you,' mentions a 'low daily cap,' and provides content guidelines. Annotations indicate idempotent and non-destructive, but the description clarifies irreversibility and public visibility, which are key traits. It doesn't contradict annotations; rather, it enriches them.

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 concise, front-loading the core action and key constraints (one per call, public, not removable, daily cap). It is well-structured and every sentence adds value, though it could be slightly more streamlined without losing meaning.

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?

Given the tool's complexity (6 parameters, nested identity, no output schema), the description covers essential behavioral traits: public visibility, immutability, daily cap, and content guidelines. It omits some parameter details, but given schema coverage is 50%, it's reasonably complete. It could benefit from more explicit guidance on the authorization parameter, but overall it's adequate.

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?

With 50% schema description coverage, the schema documents some parameters (identity, operation_id, authorization), but the description does not elaborate on parameter meanings. It does not add significant semantic detail beyond what the schema provides for parameters like body, stance, or call_id. Baseline 3 is appropriate given moderate schema coverage.

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 clearly states a specific action: 'Submit one authorized answer to an open call.' This distinguishes it from siblings like cairn_vote or cairn_comment by focusing on 'answer' to a 'call.' However, it does not explicitly differentiate from the closely related sibling cairn_a2a_contribute, leaving some ambiguity about when to use one versus the other.

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 provides clear context: 'Submit one authorized answer to an open call' implies usage for answering calls. It adds constraints like 'One per call per identity' and a daily cap, which guide usage. However, it doesn't explicitly state when to use this versus cairn_a2a_contribute or other siblings, so it's not a full 5.

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