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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety needs no restating. The description adds value beyond them by disclosing the return shape (one line per screen with purpose and slug), which the schema does not cover and which tells the agent this is a cheap overview rather than a full payload.

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 short sentences with zero padding; the catalogue scope and per-line contents come first, and the pointer to get_screen closes it. Every clause carries information an agent needs.

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 a single optional string parameter, no output schema, and full annotation coverage, the only real gaps would be return shape and routing — both are supplied. Nothing needed to call this 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?

Schema coverage is 100% and the schema already explains that area takes an area title and that omitting it returns all screens, so the baseline of 3 applies. The description adds the concrete area taxonomy ("talking to the agent, approving and controlling, watching the work"), which helps since there is no enum, but it is illustrative rather than a definitive list.

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 names a specific verb and resource ("List the screen catalogue") and states the exact granularity and contents of each entry (one line per screen: purpose and slug). It also distinguishes itself from the sibling get_screen, which returns a single screen, so an agent can pick between them without opening either schema.

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 sentence "Read one with get_screen" gives an explicit follow-on path and names the alternative tool for detail lookups. The omission behaviour ("Leave it out for every screen") is stated, but there is no explicit when-not guidance, e.g. whether to call this at all if the area is already known.

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