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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's added value is the auth scope requirement, the ordering guarantee, and the closed_at=null open-incident convention. It also explains what untrusted_fields means, which is genuine behavioral context beyond the annotations, though pagination/truncation behavior with limit is not discussed.

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?

Compact and front-loaded with the access prerequisite, then the core behavior, then the untrusted_fields note. Every clause carries information, though the last clause is somewhat densely packed and mixes a return-field concept into a description that leads with invocation requirements.

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 usefully compensates by explaining the closed_at=null convention and the meaning of untrusted_fields in the returned data, and it states the auth requirement. What is missing is any note on ordering/pagination interaction with limit or how many incidents constitute a page.

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 100%, so both id and limit are already fully documented with defaults and max. The description adds nothing about parameter syntax or interaction (e.g. behavior at the 200 cap), so the baseline 3 applies.

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 ('Lists a monitor's recent incidents') with useful scope detail: newest-first ordering and the closed_at=null convention for open incidents. It does not name or contrast the obvious sibling list_open_incidents, so an agent must infer the boundary itself, which keeps it out of the top band.

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 gives one concrete prerequisite ('Requires the read scope or higher'), which is real usage guidance. However it never says when to choose this over list_open_incidents or get_incident, and gives no exclusions, so the routing decision is only implied.

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