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

Annotations already carry the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the bar is lower. The description adds genuinely useful context beyond annotations: 'Empty list is 200' prevents misinterpreting an empty result as an error, 'House probes are not listed' discloses filtering behavior, and 'Occupancy unchanged' confirms no side effect on occupancy state. No contradiction with annotations.

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?

Four terse, single-purpose sentences with zero filler. Each sentence earns its place: verb+resource, return scope, response semantics, filtering behavior, and side-effect guarantee. The most identifying information is front-loaded.

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 read-only list tool with an output schema, fully documented parameters, and safety annotations, the description covers the key operational caveats an agent needs: how to interpret an empty response, what is excluded from results, and that the call leaves state untouched. Nothing critical appears 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 description coverage is 100% — all four auth-related parameters (nonce, leave_token, controller_signature, controller_public_key) have detailed schema documentation. The description adds no parameter-level information, so the baseline 3 applies; the schema does the heavy lifting.

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 the specific verb+resource ('GET /api/card') and clarifies the return scope ('Published public cards'). This makes the listing intent clear and implicitly distinguishes it from card_get (individual fetch) and card_publish (write operation), though it never names those alternatives explicitly.

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?

There is no when-to-use guidance, no mention of alternatives, and no exclusion criteria. With 40+ siblings including other list tools like plaza_list and rooms_list, an agent receives no routing help to decide between card_list and similar endpoints.

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