Update Direct Cost Item

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

Beyond annotations, description adds concurrency behavior (409 conflict), batch size limit, required parameters. No contradiction with annotations (readOnlyHint=false, destructiveHint=false). Covers key behavioral traits for a mutation tool.

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?

Description is front-loaded with purpose and covers key points. Some redundancy in phrasing ('Update a specific Direct Cost Item' and 'Use this to update an existing Direct Costs'). Could be tightened, but overall efficient.

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?

Covers main behavioral aspects (concurrency, batch limit) but lacks details on response structure (no output schema, only says 'returns modified object'). Does not explain the nested direct_cost object or attachments beyond schema. Adequate but not comprehensive.

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 3. Description adds minimal value: reiterates required params (already in schema) and mentions 'only the supplied fields are changed' which implies partial update. Does not explain the direct_cost or attachments parameters beyond 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 it updates a specific Direct Cost Item and returns the modified object. However, it does not explicitly differentiate from sibling tools like update_direct_cost_line_item or sync_direct_cost_items, though the update action is distinct.

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?

Provides explicit guidance on when to use: updating existing Direct Costs. Also details limitations: batch size limit of 100 line items, no concurrent requests, and 409 conflict error. Does not mention alternatives or when not to use, but context is clear.

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