Cost Locations: add cost location

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

Annotations already indicate write and non-idempotent, but the description adds concrete consequences: 'calling twice may create duplicates' and the recommendation to check the list first. This goes beyond the annotation by explaining the risk and mitigation. Slight redundancy but still valuable.

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?

The description is well-structured with a clear heading and front-loaded warning. It repeats 'Not idempotent' twice, which is mildly redundant, but overall it's efficient and each sentence serves a purpose. The generic opening about creating records is somewhat redundant with the title and annotations.

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?

The tool is simple with only two parameters and has an output schema, so the description need not detail return values. It covers the core behavioral risk (duplicates) and provides usage guidance. Missing details like permissions or format specifics are not critical given the schema and annotations.

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?

The input schema already provides full descriptions for both parameters (code and name) with 100% coverage. The description does not add any additional meaning or nuance about the parameters, so the baseline score of 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 clearly states the verb 'add' and the resource 'cost location', and even gives the use case 'create a cost centre before referencing it from a posting'. It distinguishes itself from siblings like cost_locations_list, cost_locations_update, and cost_locations_delete by explicitly saying 'add'.

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 guidance on when to use this tool: 'Use to create a cost centre before referencing it from a posting.' It also warns against duplication and directs the agent to check cost_locations_list first, which is an explicit alternative and a condition for use.

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