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

Annotations already indicate readOnly=false, so mutation is known. The description adds a valuable behavioral detail: 'If the request was waiting for your input, it will automatically move back to in_progress.' This is beyond what annotations or schema convey. It does not disclose all side effects (e.g., notifications), but given annotation coverage, this is solid.

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?

Three informative sentences, front-loaded with purpose, then usage, then a behavioral note. Every sentence earns its place; no verbosity or filler.

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 mutation tool with no output schema, the description covers purpose, usage scenarios, and a key side effect. Sibling context (get_support_requests, submit_support_request) further clarifies its role. Not exhaustive (no error conditions or closed-request behavior), but adequate for the tool's complexity.

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, so baseline is 3. The description adds minimal extra meaning, e.g., 'follow-up message' maps to body and 'logs/evidence' hints at attachmentJson. No significant semantic enhancement beyond the schema.

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 uses a specific verb ('Add a follow-up message') and clearly identifies the resource ('existing support request'), distinguishing it from sibling tools like submit_support_request (creates new) and get_support_requests (reads). This is a clear, unambiguous statement of purpose.

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 explicitly states use cases ('provide additional context, respond to questions, or add logs/evidence') and implies when not to use it (e.g., for creating new requests). It does not name alternatives explicitly, but the context is clear enough to guide an agent. Lacks an explicit exclusion or 'when not to use' clause, so not a 5.

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