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

Annotations declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, and the description's mutation framing is consistent with them. It adds that a result file is returned, but says nothing about whether the original is left untouched, permission/auth needs, or what the optional password field is for — meaningful gaps for a security-related mutation.

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 short sentences with the core action front-loaded and no padding. The middle sentence 'Accepts pdf' is largely redundant with the schema's file constraint, a minor wasted clause.

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 one-required-parameter tool with a nested files object and full schema coverage, the description covers the essentials. It still omits the one thing an agent would likely get wrong — how the password option interacts with an already-encrypted input — and there is no output schema to lean on beyond 'returns the result file'.

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 100%, so the schema already documents files, upload_id, content_base64 and the 50 MB limit; the baseline of 3 applies. The description does not clarify the ambiguous 'options.password' field (user vs owner password, default empty string), which is exactly the kind of nuance the schema cannot convey.

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 ('Remove the password protection from a PDF'), which is immediately distinguishable from the sibling protect-pdf. It stops short of naming that inverse sibling explicitly, but the action itself 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?

No when-to-use guidance and no reference to the obvious alternative (protect-pdf) or to what to do if the file is not password-protected. 'Accepts pdf' restates the schema rather than advising the caller.

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