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

With no annotations, the description adds gateway credential and charge context: 'Uses the caller's OpenAny gateway credentials. Charges and authorization are determined by the gateway.' This is useful but vague and does not describe read-only safety, rate limits, or pagination beyond the schema's gsrlimit cap.

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?

The description is short and front-loaded with the core action and follow-up use. The gateway credential and charge sentence is slightly boilerplate but not excessive.

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 7-parameter search tool with full schema coverage and no output schema, the description covers the search scope and how to use the result. It is mostly complete, though it could clarify that only up to 10 files are returned and that the operation is read-only.

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 parameter meanings are already fully documented. The description only adds that the keyword is used to search the file namespace and that the returned title is a 'File:' title, which is marginal 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 description states a specific verb and resource: 'Search the Commons file namespace by keyword.' This clearly distinguishes it from a general Wikimedia search, though it does not name the sibling tool by its exact identifier.

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 gives clear follow-up guidance: pass the returned 'File:' title to Wikimedia Commons File Details. It does not describe when not to use this tool or name alternatives for other search scopes.

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