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

Annotations already establish the safety profile (readOnlyHint, idempotentHint, destructiveHint), and the description adds valuable non-obvious behavior: it requires an agency API key, only ever returns the calling agency's own leads, lists enquiry sources, and explains the move from inbox to pipeline. This goes well beyond what annotations alone convey.

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?

The main purpose is front-loaded in the first sentence, followed by clear usage guidance and a genuinely important empty-inbox clarification. Every sentence earns its place; the length is justified by the need to prevent false negatives and sibling confusion.

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?

The description covers auth scoping, ownership, ordering, sources, and the pipeline distinction, which is a strong level of context. However, with no output schema present, it does not describe the shape or fields of a returned lead, nor any pagination behavior beyond the limit parameter, leaving a small completeness gap.

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 schema already documents 'since' and 'property_reference', and 'limit' has useful defaults and bounds. The description adds 'newest first' and 'what came in today' context, which helps interpret the ordering and recency, but it does not substantially explain parameter semantics beyond what the schema provides. With 67% schema coverage, the description neither fully compensates nor is redundant.

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 states a clear verb and resource: 'List recent enquiries (leads) for YOUR agency's CRM - newest first.' It also distinguishes itself from my_pipeline by defining the inbox versus pipeline lifecycle, so an agent can confidently tell these siblings apart.

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?

It explicitly says when to use the tool: when the agent asks what has just come in, e.g. 'what came in today?'. It also gives an exclusion and alternative ('for those, use my_pipeline') and clarifies that an empty inbox is not equivalent to having no leads, preventing a common misinterpretation.

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