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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed world), and the description adds substantial context beyond them: raw filesystem access, admin capability requirement, dependence on the site's write access mode, the 800-file cap with no indication that more exist, and the skipping/refusal of AlphaBridge's own folders.

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 core purpose is front-loaded in the first sentence, and every subsequent clause carries real information (return shape, cap, error behavior, folder exclusions, auth). It is dense rather than bloated, though the run-on packing of constraints makes it slightly heavier than necessary.

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 read-only, single-optional-parameter tool with no output schema, the description supplies everything an agent needs: what it returns (base plus sorted relative file paths), the cap and its ambiguity, the error case, the excluded folders, and the capability requirement.

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 100% and the single subdir parameter is fully documented there. The description nonetheless adds meaning beyond the schema: it clarifies the recursion behavior and that AlphaBridge folders (ab-mcp-sessions, ab-mcp-exports, ab-mcp-undo) are refused as subdir, which the schema does not state.

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 with precise scope: 'List the files in the uploads directory (wp-content/uploads) or one subfolder of it, recursively.' It also explicitly distinguishes itself from the sibling wp_list_media by noting that attachments with metadata are listed there instead.

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 the alternative explicitly ('Attachments with their metadata are listed by wp_list_media') and the preconditions that select this tool: administrators only (manage_options) and only when the site's write access is on. A missing subfolder being an error is also stated, leaving little to infer.

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