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

Annotations already cover read-only, idempotent, non-destructive semantics, so the bar is lower, yet the description still adds the prerequisite that signing is an opt-in server setting and enumerates the exact failure modes (missing, malformed, unsigned, signature failure) that yield valid:false. It stops short of describing the success payload shape or any rate/auth considerations, so it is strong but not exhaustive.

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-loaded with the core action, then prerequisites, then the negative scope, then error behavior. Dense but every clause carries information; the only cost is that the middle sentence packs several constraints into one long clause chain.

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?

There is no output schema, so the description must carry return semantics, and it does by explaining the valid:false plus reason outcome and when that is expected rather than an error. For a single-parameter verification tool with a nested token object, nothing an agent needs to call it correctly is missing.

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 already 100% and the nested groundingProof fields are documented in the schema, so the baseline is 3. The description pushes past the baseline by constraining usage — the object must be passed back exactly as received and unmodified — which is a real semantic constraint the schema alone does not state.

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 and resource ('Verify a Magist grounding-proof token') and immediately scopes it to the 'groundingProof' field on regulation/control records, which no sibling tool touches. The purpose is unmistakable versus lookup_regulation or search_regulations.

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?

Explicitly says where the token comes from (GET /api/v1/regulations/{id} or /api/v1/controls/{id} with signing enabled) and explicitly warns that MCP tool responses do not carry these tokens, which prevents a whole class of misuse. It also states the boundary condition — it does NOT verify legal correctness or obligation applicability.

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