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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds a behavioral precondition (one identifier required) but its remaining content is a listing of returned fields, which the output schema already documents.

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?

Two sentences, no filler, with the core behavior front-loaded and the precondition stated last. Every clause carries information.

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 an output schema present, the description need not explain return values, and annotations cover the safety profile, so the definition is nearly self-sufficient. The residual gap is the lack of guidance on identifier precedence and on the conditional project_slug 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 only 33% – file_id and document_id have no schema descriptions. The description partially compensates by naming both and clarifying that document_id is numeric, plus the at-least-one rule. It says nothing about project_slug's conditional requirement or what happens if both identifiers are supplied, so the gap is only partly filled.

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 ('Returns') and resource ('a saved document') plus the accepted identifier forms, so the agent knows exactly what it fetches. It does not name or distinguish itself from any sibling, but the sibling list contains no other single-document fetch, so the ambiguity risk is low.

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 supplies a precondition ('At least one document identifier is required') but gives no guidance on when to use file_id vs document_id, or when this tool is preferable to related reads like jobs.get or rows.search. Usage is implied rather than stated.

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