List Contact Properties

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds a genuine behavioral instruction beyond structured fields – presenting the returned ids/timestamps only on request – which is useful output-handling context.

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 tight sentences, front-loaded with the core purpose followed by a presentation caveat. Nothing is wasteful, though the second sentence is a slightly tangential aside rather than essential task information.

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 no output schema and fully documented params, the description conveys what is returned (property keys usable as merge tags) and how to surface them. Pagination behavior is left to the schema, which handles it adequately.

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% and the schema fully documents after/before/limit/search, so the baseline is 3. The description adds no parameter-level meaning (e.g. it never mentions searching or pagination), so it neither compensates nor detracts.

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 (List) plus the exact resource (organization's custom contact fields) and clarifies what those fields are: the keys a contact's `properties` can hold and merge tags in messages. This clearly distinguishes it from the singular get-contact-property / create-contact-property siblings.

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?

Usage is only implied – the agent can infer this is the way to enumerate available contact property keys, but no explicit when-to-use, when-not, or alternative (e.g. get-contact-property for a single field) is named. Adequate but leaves routing to inference.

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