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

Annotations already provide readOnlyHint: true, covering the read-only nature. The description adds valuable behavioral context by explaining that includeAssignments is the source of assignmentId for unassigning, and notes that it returns policies 'with their rules'. This goes beyond the annotation and helps the agent understand the tool's output semantics.

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 concise sentences, front-loaded with the primary purpose. The second sentence adds the key usage nuance without fluff. Every sentence contributes meaning, making it efficient and well-structured.

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?

The tool is simple with only two optional parameters. The description covers the core action, the key optional parameter behavior, the use case, and the alternative tool. No output schema exists, but the agent can infer the list structure. Nothing essential is missing for correct invocation.

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 both parameters documented. The description adds significant meaning beyond the schema by explaining the purpose of includeAssignments (to get environments, specs, monitors attached) and where assignmentId comes from. This extra context helps the agent decide when to set it.

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 verb ('List') and resource ('alert policies of a project'), and distinguishes it from the sibling get_alert_policy (which retrieves a single policy) and manage_alert_policy (for mutations). This makes the tool's purpose unambiguous.

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?

Explicitly states when to use this tool ('to browse policies or find an id') and explicitly names the alternative for mutations ('to create or change one use manage_alert_policy'). It also notes the requirement for project context, giving clear guidance on when and how to use it.

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