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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds useful context beyond that: the compact/full payload tradeoff and that compact omits metaData blobs, which affects token cost and output shape. Pagination/cursor behavior is unaddressed, keeping it below 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 dense sentences, front-loaded with the verb and action list, then the mode default, then exclusions. No filler; every clause carries routing or payload 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 15-parameter tool with a nested filters object and no output schema, the description covers actions and the mode default but is silent on pagination, filter semantics, and which export action consumes which fields. Enough to select the tool, not enough to call it confidently without schema reading.

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 13%, so the description must compensate, and it does explain the two most important semantics: the action enum and the default of mode. However, many of the 15 parameters (page, limit, cursor, leadId, groupName, timeRange, searchTerm, leadFilters, searchField, propertyFilter, useAgentLeadsEndpoint) get no explanation, leaving the agent to infer their meaning.

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 (read) and resource (CRM leads) and enumerates the four actions it supports. It actively distinguishes itself from leads_write and clients_read, so an agent can route without opening the schema.

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?

Gives explicit when-to-use guidance: default to mode=compact for lists, use mode=full only when complete objects are needed, and prefer action=get for a single lead. It also states negative conditions ('does not create/update', 'not for client accounts'), routing the agent to the right sibling.

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