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

Annotations already declare read-only, idempotent, and non-destructive behavior, so safety is covered. The description adds genuine beyond-annotation context: results are restricted to 'authorized' sources, completion is separate from human review, and counts measure fragments (not pages or cells) - an important interpretation caveat that prevents misuse of the returned numbers.

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?

Front-loaded with the 'List' verb and then three tight sentences that each carry distinct information (scope, usage sequence, interpretation caveat). Dense and jargon-laden, but there is no filler or repetition.

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?

With no output schema, the description carries the return-value burden and does enumerate the returned fields (sources, keys, revisions, passage counts, gaps/blockers), plus a caveat about what counts mean. Pagination is mentioned but not specified, and there is no output-format detail, leaving a small gap.

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?

Only one parameter (projectId) and schema description coverage is 100%, with a schema note clarifying it is a Helvabase ID and not a local path. The description adds no parameter-level detail, so the schema does the entire job - the baseline 3 for high coverage is appropriate.

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 clear verb+resource ('List authorized full-document sources') and scopes it explicitly, enumerating the specific data returned: source keys, revisions, received vs model-declared passages, extraction/OCR gaps and blockers. It is heavier on domain jargon ('read/context/analysis revisions') but an agent can tell this is a coverage/inventory read rather than a document content read. It does not name a specific sibling, so it stops short of full differentiation.

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?

'Use before analysis, then paginate every required source' gives a clear when-to-use and a required follow-up procedure (pagination per source). It doesn't name a concrete alternative tool, but the lifecycle placement relative to analysis is unambiguous enough to route the agent.

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