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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds meaningful context beyond them: the payload varies by channel (email address, SMS enquiry text, phone number plus call recording), and it discloses the Cotlet API key requirement. This is solid behavioral disclosure for a read tool.

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 channel-specific payload breakdown is informative, but the opening is repetitive ('One lead with...' followed by 'Returns one lead.'), which wastes space. Front-loaded but not tight.

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?

No output schema exists, so the description carries the return-value burden and does so by enumerating channel-dependent contents, plus the auth requirement. It is complete enough to call correctly and interpret the result; only the exact response shape (field names, timestamps) is left unspecified.

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 documents lead_id with its source ('Lead ID from list_leads'). The description adds no parameter-level detail beyond the schema, so the baseline of 3 applies.

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 (fetch one lead) and describes what it contains, distinguishing it from the sibling list/export lead tools. The phrasing 'the contact details Profolio shows for its channel' is awkward and slightly obscures what is being retrieved, keeping it below a 5.

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 schema notes lead_id comes 'from list_leads', so an agent can infer this follows a list call, but the description itself gives no explicit when-to-use or when-not-to-use versus bayut_list_leads or bayut_export_leads. The auth prerequisite is stated but that is a precondition, not selection guidance.

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