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

The annotations already declare readOnlyHint=true, so the tool's non-mutating nature is established. The description adds useful behavioral context beyond that: it enumerates what gets listed (documents and uploaded assets) and signals that the output is intended to supply exact paths. There is no contradiction with the annotations.

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 two sentences with no filler. The core action and scope are front-loaded, and the usage guidance follows concisely. Every sentence earns its place.

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 simple, single-parameter, read-only listing tool, the description covers what is listed, the project scope, and how the result should be used with sibling tools. The absence of an output schema is mitigated by the clear statement that the tool returns exact paths for later read/update operations.

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?

The only parameter, project_id, is fully documented in the input schema as coming from list_projects. With 100% schema description coverage, the tool description does not need to repeat parameter details. It adds only contextual scope about the project, which is adequate.

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 uses a specific verb and resource: it lists all documents and uploaded assets within a user's letX project. It clearly distinguishes itself from read_project_file and update_project_file by stating it provides exact paths, making the tool's scope and role 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?

The description explicitly says to use this tool before read_project_file or update_project_file to get exact paths. This names the relevant alternative tools and gives a clear sequencing rule, so an agent knows exactly when to invoke this tool.

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