Adds Existing Labels To Specified Resources.

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

The description adds valuable behavioral details beyond annotations: non-idempotency ('calling it again creates another record'), common HTTP error codes (401/403/404), and parameter defaults. However, it also contains the contradictory statement 'Creates the existing label and returns it with its new id', which misrepresents the operation as creating a label rather than an association.

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 a single block that front-loads the purpose and packs in prerequisites, error handling, and endpoint info. It is slightly verbose (repeats the endpoint path) and includes the confusing 'Creates the existing label' phrase, but overall earns its length with useful details.

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 4-parameter tool with no output schema, the description covers many aspects: purpose, preconditions, defaults, non-idempotency, common failures, and API location. However, it fails to clearly explain the response structure or the optional resource_guids parameter, and the misleading 'Creates...' statement reduces completeness.

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 the baseline is 3. The description adds defaulting behavior for company_id and project_id, but this conflicts with the schema marking them as required. It does not clarify the role of resource_guids (optional in schema, though the first sentence implies resources are needed), leaving some semantic gaps.

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 identifies the action ('Associates one or more existing labels with one or more resources') and distinguishes it from sibling tools like remove_existing_labels_to_specified_resources. However, the misleading phrase 'Creates the existing label' introduces ambiguity about whether the tool creates labels or associations.

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 useful context: labels must pre-exist, company_id/project_id can default from procore_set_config, and required parameters are listed. It does not explicitly contrast this tool with alternatives or state when not to use it, leaving usage mostly implied.

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