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

Annotations only supply destructiveHint=true, and the description adds real context: it modifies live status-page data and can notify subscribers, plus it names the endpoint (POST /v1/{page_id}/incidents) and the return (the created incident). It does not state permission requirements or whether notifications are default-on, so it stops short of a 5.

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 dense sentences with the effect warning front-loaded, required vs optional params summarized compactly, and endpoint/return noted last. No wasted clauses.

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?

For a 9-parameter mutation with no output schema, the description covers the key facts an agent needs: required field, optional fields, side effects, and that the created incident is returned. Remaining gaps (notification defaults, permission/error behavior) are minor given full schema coverage.

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 the schema already documents every parameter including enum values and formats. The description usefully flags name as required and lists the optional fields, but adds no syntax or semantic detail beyond what the schema provides. Baseline 3 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?

Specific verb+resource ('CREATES a new incident') with the scope stated — it modifies live status-page data. The name instatus_create_incident plus the create-vs-update framing makes it distinguishable from instatus_update_incident and instatus_create_maintenance.

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?

Clear context — create a new incident, provide name as required, everything else optional — and the mutation warning signals when care is needed. It does not explicitly route the agent to instatus_update_incident for existing incidents, so it stops short of naming alternatives.

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