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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the mutation profile is covered. The description adds real context the annotations cannot: the state-based lock after assignment/certification and the fact that the stored name is normalized (diacritics stripped, unsupported characters replaced with dashes). It stops short of saying what error or state the caller observes when the lock applies.

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, both dense with information, and the primary action is front-loaded ahead of the constraint and the normalization caveat. No filler or restatement of the title.

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 two-parameter mutation tool with no output schema, the description covers the action, the eligibility window, the lock condition, and the name transformation — enough to call it correctly. It omits failure behavior when the document is already locked and any permission requirements, which are the only remaining gaps.

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 50%: `document_id` is documented in the schema, while `name` has no schema description and the constraints (minLength 1, maxLength 255) live only in the schema. The description adds meaningful semantics for the name value — the normalization rules that transform whatever is submitted — which partially compensates, but it says nothing about the identifier format or uniqueness. Baseline 3 given the mixed 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?

States a specific verb and resource ('Update a document's name') with no ambiguity, and no sibling tool performs the same operation, so the agent can route to it unambiguously. The scope is narrowed immediately rather than leaving the reader to infer it.

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?

Gives an explicit eligibility window ('only allowed before any assignment is created ... while the document is in `uploaded` or `metadata_ready` status and has no signers yet') and an explicit when-not condition ('once the signature process has started or the document is certificated, the name is locked'). The agent knows exactly when to call and when to avoid it, with no alternative tool competing for the same job.

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