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

Annotations provide destructiveHint: true, and the description adds that it modifies live status-page data and can notify subscribers. This goes beyond annotations by specifying the impact on subscribers and providing a usage example. However, it does not cover all behavioral nuances (e.g., idempotency).

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?

The description is concise (two sentences plus endpoint info), front-loaded with 'UPDATES', and contains no unnecessary words. Every sentence contributes to understanding the tool's purpose and behavior.

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?

Given 10 parameters, full schema coverage, a destructive annotation, and no output schema, the description adequately covers context. It notes the HTTP method and return value. Minor gap: no mention of field dependencies (e.g., required fields for certain status changes).

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 100% with parameter descriptions. The description adds value by advising to send only changed fields, which is not captured in the schema. This enhances understanding beyond the schema alone.

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 clearly states the action ('UPDATES an existing incident by id'), indicates it modifies live data, and provides example status transitions ('MONITORING or RESOLVED'). It distinguishes the tool from sibling tools like instatus_create_incident and instatus_delete_incident.

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 explicit guidance 'Send only the fields you want to change' helps the agent use the tool efficiently. It implies this is for updating existing incidents, contrasting with create/delete siblings, but lacks explicit 'when not to use' or alternative tool references.

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