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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: rubric text, rules, and evaluator URLs are write-only and never echoed, which prevents the agent from expecting that content in the response.

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?

Two tight sentences with the primary purpose front-loaded and the write-only caveat immediately following. The enumeration of returned fields is somewhat redundant given that an output schema exists, costing a little space that could have been trimmed.

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?

With an output schema present and annotations covering the safety profile, the description supplies the one thing structured data cannot: the write-only redaction behavior. The field list duplicates the output schema, so the description is complete but not maximally efficient.

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?

The tool takes zero parameters, so the baseline is 4. There are no argument semantics to explain and the description appropriately spends no space on them.

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 ('registered critics') and enumerates the returned attributes including the tier enum values (rules|rubric|evaluator). It distinguishes itself from the mutation siblings by explicitly naming register_critic and delete_critic.

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 second sentence routes the agent to the correct alternatives for write operations: register_critic for upsert and delete_critic for removal. There is no explicit 'when not to use' guidance, but the read-vs-mutate split is clear from context.

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