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

With only destructiveHint=true in annotations, the description carries most of the burden and does well: it discloses the authorization model, that clearPassword removes protection, and that replacing content requires notesOnReplace. It does not explain the return payload or whether updates are atomic/reversible, but the destructive side effects of replacement are surfaced.

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?

Four short sentences, front-loaded with the action, then auth rules, then the two mutating behaviors. No filler; the only cost is that it reads as a compact rule list rather than a narrative.

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 9-parameter destructive mutation with no output schema, the description covers the critical unknowns: authentication, content-vs-metadata replacement, and the notesOnReplace requirement. Minor gaps remain (e.g., behavior of unknown title/fileName combinations, confirmation of success), but nothing essential 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 description coverage is 78%, so the schema already documents most parameters (including the detailed notesOnReplace semantics). The description restates markdown/metadata/clearPassword behavior at a high level, adding cohesion but little information 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 opening 'Update a document' gives a clear verb+resource, and the following sentences specify what updating entails (content replacement vs. metadata field replacement, password clearing). It does not explicitly contrast itself with the create/delete/get siblings, but the operation is unambiguous.

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 states the auth conditions (password or owner API key for protected documents; open for unprotected) and that metadata fields replace individually, which implies when to use each mode. However there is no explicit 'use X instead when Y' guidance and no mention of the sibling tools, so alternatives are left to inference.

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