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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds useful behavioral context: the result is scoped to the account's accessible deployments, and the active deployment for other tool families can be switched via the ?deployment=<slug> query parameter.

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 sentences with zero waste: the core operation and scope appear first, followed by the session/query guidance. Every sentence earns its place without repeating schema or annotation details.

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 zero-parameter, read-only list operation with an output schema and full safety annotations, the description provides the essential extra context: account scope and the deployment-switching mechanism. Nothing needed to invoke the tool correctly is missing.

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?

The input schema has zero parameters, so the baseline is high. The description goes further by documenting an actionable URL-level switch, ?deployment=<slug>, which is not represented in the schema and is important for controlling which deployment subsequent tools act on.

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 opens with a concrete verb and object, 'List every deployment this account can access,' adding account-level scoping to the title. This makes it clearly distinct from deployment_create, deployment_update, and deployment_delete without needing to name them.

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?

It frames the tool as the way to enumerate all accessible deployments and connects this to the session-bound deployment concept, implying this list is used to discover the slug for other tools. It does not explicitly name alternatives, but the context is clear enough for an agent to select this tool appropriately.

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