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

Annotations indicate idempotent mutation; description adds that it returns the new override value and effective resolved value after fallback, providing behavior beyond what annotations convey. No contradictions.

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 sentences, front-loaded with purpose and return info, no unnecessary words.

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 two-parameter tool with output schema, the description explains purpose, return values, and fallback logic, making it fully self-contained without needing external context.

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 covers 100% of parameters with descriptions. Description does not repeat or significantly expand on schema details, so baseline 3 is appropriate.

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 the tool overrides read-receipt settings per group for the caller, with precise verb 'set' and resource 'group read-receipt override'. It also clarifies it returns both the new override and the effective resolved value, distinguishing it from other group conversation tools.

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 indicates it is for per-group override of read receipts, with fallback to user-level preference. While it doesn't explicitly exclude alternatives, no sibling tools have similar functionality, so the context is clear.

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