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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavior: it returns an exists:false shape rather than erroring when nothing has been generated, which is exactly the kind of non-obvious outcome an agent needs.

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, front-loaded with the action and the returned content, with the edge case and its remedy in the second. No filler.

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?

Output schema and annotations are rich, and the description covers the key non-happy-path (exists:false) plus the remedy. The only shortfall is the absent report_id semantics, which is minor for a one-parameter read.

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 0%, so the schema does not document report_id at all; the description only implies it by saying "for a report." With a single, largely self-evident identifier this is adequate, but it adds no format, sourcing, or lookup detail.

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 ("Fetch the pre-buy diligence checklist header for a report") and enumerates what the header contains (generation status, progress counters, knowledge score). It does not, however, distinguish itself from the sibling get_diligence_progress, which plausibly overlaps on the progress-counter content.

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 a concrete conditional path: if no checklist exists, call generate_diligence_checklist instead. That is real routing guidance, though it never contrasts this tool with get_diligence_progress or list_diligence_items for the case where a checklist does exist.

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