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

The description discloses the HMAC verification mechanism and the success condition ('Returns valid=true when the HMAC matches'), adding behavioral detail beyond the readOnlyHint/openWorldHint annotations. It does not describe failure behavior, but the core behavior is transparent.

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-load the purpose, then give precise usage instructions and the return condition. Every clause adds value, with no repetition of schema data or annotation information.

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?

The description covers what to pass and what result to expect, which is adequate given no output schema. It could explicitly state the behavior when the signature does not match, but for a simple verification tool the provided information is nearly complete.

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 schema provides no descriptions and payload is an untyped empty schema, yet the description fully specifies the semantics: payload must be the envelope without verification_signature and signature is the received signature. This fully compensates for the 0% schema description 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 states a specific verb ('Verify') and resource ('previously-served FlareWatch MCP response') and clearly differentiates this tool from sibling data-retrieval tools. It establishes that this tool authenticates the origin of a response rather than fetching or comparing data.

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?

It provides a concrete use case ('cross-AI citation verification') and explains the exact input format required. It does not explicitly list when-not-to-use or alternative tools, but since no sibling performs verification, the contextual guidance is sufficient.

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