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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description usefully adds that the list is scoped to 'open' investigations and that a single read includes claims and evidence. It leaves open whether closed investigations are retrievable by id, which is a real behavioral gap.

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?

One sentence, front-loaded with the list mode and then the read mode, with no filler. It is appropriately sized, though the two modes could be separated for slightly faster parsing.

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?

No output schema exists, so the description carries the return-value burden, and it does name the payload (claims and evidence) for the read case. The list-case return shape and the closed-vs-open scope question remain unaddressed, but the essentials for calling the tool are present.

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% for the single id parameter, so the description must compensate. It does convey that id selects one investigation and that omitting it lists all open ones, but says nothing about id format, validity, or error behavior when an unknown id is passed.

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 gives specific verbs and a resource: 'list open investigations' and 'read one with its claims and evidence.' The dual-mode behavior is legible from a single sentence, so an agent knows what the tool returns. It does not, however, differentiate itself from siblings like claim or add_evidence, which share the same domain vocabulary.

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?

Usage is only implied: omitting id yields a list, supplying id reads one investigation. There is no explicit when-to-use or when-not-to-use guidance and no alternative tool is named, so an agent must infer the mode selection from the parameter's optionality.

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