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

Annotations already declare readOnlyHint=false and destructiveHint=false, indicating a mutation that is not destructive. The description adds the precondition that the sales tax must already exist on the entity, but does not disclose whether the update is partial or full replacement, or any side effects. This meets the reduced bar but adds only modest context beyond the annotations.

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 sentences, no filler. The action is front-loaded, and the alternative routing is given in the second sentence. Every word earns its place.

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 13-parameter mutation tool with full schema coverage and no output schema, the description is sufficient: it states the operation, the precondition, and routes additions to the correct siblings. The lack of return-value documentation is a minor gap since no output schema exists.

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%, so the schema fully documents all 13 parameters. The description only re-emphasizes that 'id' refers to an existing sales tax, which the schema already states ('Id of the sales tax to update'). 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?

States a specific verb ('Update') and resource ('existing sales tax on an entity'), and explicitly differentiates from the add_* siblings by the 'already on an entity' qualifier. This is immediately distinguishable from add_entity_salestax and related tools.

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?

Explicitly names the three addition alternatives and the condition that selects them: 'To add a new sales tax use ...'. It clearly tells the agent when to use this tool (update existing) vs when not (adding new).

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