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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description's only added value is the concrete endpoint path GET /v1/Time/CostCodes/{id}, which is mildly useful for troubleshooting but adds no behavioral detail such as error behavior on missing ids.

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 fragments, front-loaded with the outcome and followed by the backing endpoint; nothing extraneous. It is arguably too terse to be maximally useful, but no sentence is wasted.

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 single-record read with one well-documented parameter and annotation coverage, most of the contract is present. The notable gap is that no output schema exists, yet the description says nothing about what a cost code record contains or how a not-found case behaves.

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?

There is a single parameter and schema description coverage is 100% ('Arcoro cost code id.'), so the schema fully carries parameter meaning. The description repeats the concept of an id but adds no format, range, or sourcing guidance 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?

States a specific verb-and-resource pair ('One cost code by id') plus the underlying endpoint, which lets an agent distinguish it from exaktime_list_cost_codes at a glance. It stops short of explicitly naming that sibling, but the singular 'one' vs. list distinction is conveyed.

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?

'One cost code by id' implies retrieval of a single known record, which implicitly differentiates it from the list and create siblings. However, there is no explicit when-to-use statement, no mention of prerequisites, and no guidance on what to do if the id is unknown.

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