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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the useful non-annotated detail that the response includes contact and company data, which matters because there is no output schema, but it says nothing about error behavior for missing IDs or permissions.

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?

One tightly written sentence with the resource and return contents front-loaded and zero filler. It is appropriately sized for a single-parameter read, though it is arguably too terse to carry any routing 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 simple read-by-ID tool with complete schema coverage and readOnly annotations, the description supplies the one missing piece – what the call returns – even without an output schema. Nothing essential to invoking it correctly is absent, though sibling routing would make it airtight.

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 single parameter is fully documented in the schema, including the note that the ID is returned at creation. The description only echoes 'by ID' and adds no format, range, or sourcing detail beyond the schema, so the baseline 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?

The description states a specific verb and resource ('Retrieves a lead by ID') and even summarizes the payload (contact details, company information), so an agent immediately knows what it fetches. It does not, however, explicitly distinguish itself from siblings like list_leads or get_lead_conversation, leaving that differentiation to inference.

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 guidance on when to use this tool versus the many sibling read tools (list_leads, get_lead_conversation, get_icp). The 'by ID' phrasing weakly implies single-record lookup, but no exclusions or alternatives are stated.

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