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

Annotations already declare readOnlyHint=true, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds genuine value beyond that by disclosing the returned fields (titles, floors, last changes) and the sort order (newest first). It does not mention any result cap or pagination, which is the only remaining behavioral gap.

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, zero filler. The usage trigger is front-loaded ahead of the output description, which is the right ordering for an agent deciding whether to call.

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 input parameters and no output schema, the description carries the return-value burden itself and does so for the main fields and ordering. A note on result size or whether all plans are always returned would close the last gap for a simple list tool.

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 tool takes no parameters, so there is no parameter meaning to convey and the baseline applies. The description correctly implies the call is unfiltered ('the plans in their account') rather than suggesting optional scoping arguments that do not exist.

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 the plans in their account') and names the fields returned plus the ordering, so the agent knows exactly what comes back. It does not explicitly differentiate from describe_plan, which also deals with a single plan, so a user 'mentioning one of their plans' could plausibly route either way.

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?

Gives a concrete conversational trigger ('when someone mentions one of their plans or asks what plans they have'), which is clear context for invocation. It offers no exclusions or named alternatives, so the boundary with describe_plan and query_project is left to inference.

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