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

With no annotations provided, the description carries the burden and does meaningful work: it declares read-only safety, zero cost, a 100-item page cap, and a data-shape quirk (signal_context with reasoning, relevance score, ICP group for Vendo SDR contacts). It stops short of stating auth/permission requirements or the full return shape, which keeps it below a 5.

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?

Three short clauses with zero waste: the resource and paging cap come first, the noteworthy data attribute second, the safety/cost profile last. Every sentence adds information an agent can act on.

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 3-parameter read tool with no annotations and no output schema, the description covers safety, cost, and pagination but leaves the returned contact fields largely unspecified (only signal_context is described) and does not clarify page numbering or permission prerequisites. It is adequate but not complete.

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 only 33%: only 'id' is documented, while 'page' and 'limit' are bare. The description partially compensates by stating 'max 100 per page', which reinforces and explains the 'limit' constraint, but says nothing about how 'page' is interpreted or whether it is 1-based, leaving a real gap.

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+resource: 'Paged contacts of a custom audience.' It clearly identifies the resource and the paging behavior, but it does not distinguish itself from near-siblings such as get_audience_set_contacts, search_audience, or export_custom_audience_csv, leaving the agent to infer which retrieval tool applies.

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. 'Read-only, free' hints this is a cheap read worth preferring, and the paging note hints at iterative use, but there is no explicit when-to-use clause or named alternative for exporting or searching contacts instead.

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