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

Annotations already declare idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond that: 'Only the provided fields are changed,' clarifying partial-update semantics. It says nothing about permissions, error behavior, or whether clearing a field is possible.

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 short sentences, zero waste, with the partial-update constraint front-loaded as the second sentence. Nothing padding-like or redundant.

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 an 11-parameter mutation tool with a nested object and no output schema, the description is thin: it never states the required 'id' is the target lead, nor which field categories are editable. The exhaustive schema and the annotation set fill most of the gap, leaving the definition minimally viable rather than 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 100%, including a rich explanation of customVariables and its merge-tag semantics, so the schema carries parameter meaning. The description adds no per-parameter detail beyond the generic 'contact details' framing, which is the baseline expectation at full coverage.

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: 'Updates a lead's contact details.' An agent can distinguish it from get_lead or delete_lead easily. However, it does not differentiate from closely-related siblings such as update_lead_category, move_lead_to_campaign, or mark_lead_meeting, which all mutate a lead in different ways.

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?

No guidance on when to use this tool versus update_lead_category or move_lead_to_campaign, and no stated prerequisites or preconditions. Usage must be inferred entirely from the name.

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