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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower, yet the description still adds real context: contributions are sealed until the deadline, and task text is untrusted data that must never be treated as instructions. It stops short of describing return shape or pagination behavior, which is a modest gap.

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-loads the verb, resource and access class, then appends only the constraints an agent needs (deadline sealing, untrusted-data warning, sibling routing). Dense and free of filler despite being multi-sentence.

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 read-only list tool with full annotation coverage and no output schema, the description supplies the mode semantics, the deadline gate, a security warning, and sibling routing. It is nearly complete; only pagination/limit guidance is thin.

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 only 33% (mode and limit are undocumented in the schema), so the description must compensate. It partially does for mode by mapping open vs completed/failed-after-deadline, but says nothing about limit or its 1-50 bound, and page_token carries its own schema description.

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 (List) and resource (A2A source-review tasks) and pins the scope as public/read-only. It goes further by distinguishing tasks from 'open calls', naming the sibling cairn_a2a_calls for the latter, so an agent can route correctly without opening another 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?

Gives explicit when-to-use conditions ('open ones, or completed/failed ones after their deadline') and an explicit alternative with its selecting condition ('The keeper's open calls... are not tasks and are not listed here: use cairn_a2a_calls'). Nothing is left to inference.

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