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

No annotations provided, so description carries full burden. It discloses that the rate value is never echoed back, which is critical behavior. It also implies a write operation, which is clear. No contradictions.

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 sentences, no fluff. The key action and constraints are front-loaded in the first sentence. Every sentence adds value.

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?

Given 6 parameters, no output schema, and no annotations, the description covers purpose, key constraints, and a behavioral trait (no echo). It lacks detail on success/failure responses but is sufficient for the agent to invoke correctly.

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%, so baseline is 3. The description adds marginal value by reiterating constraints like 'cannot set your own cost rate' (related to user_id) and 'never pass org id', but does not provide new meaning beyond the schema.

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 clearly states the tool sets the internal hourly cost rate for a single organization member, using specific verb 'set' and resource 'user cost rate'. It distinguishes from sibling bulk_update_cost_rates by specifying 'one member', and from update_user_profile by focusing on cost rate.

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?

The description provides explicit context: organization is fixed (never pass org id) and self-cost-rate-setting is prohibited. This guides when to use and important constraints, though it does not explicitly name alternative tools for bulk operations.

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