update_time_entry

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The word 'update' implies mutation, but the description doesn't state what happens to existing timer values (e.g., does updating 'start' or 'end' recalculate duration?), whether the timer must be stopped first, whether partial updates are supported, or what the response contains. For a mutation tool with zero annotation coverage, this is a meaningful gap.

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 extremely short (4 words: 'Update a time entry'), which is technically concise but under-specified rather than genuinely economical. It lacks structure because there's essentially nothing to structure. A slightly longer description explaining update semantics and key parameters would earn a higher score.

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 10-parameter mutation tool with no output schema and minimal annotation coverage, the description is inadequate. It should explain update semantics, behavior around partial updates, the tag_action enum, and timer-related constraints. The schema documents only 20% of parameters, so the description needs to compensate but provides zero additional context. This is significantly incomplete for the tool's complexity.

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 only 20% (only team_id and timer_id are described). The description adds no parameter-level detail beyond what the schema provides. The tool has 10 parameters, including nuanced ones like tag_action (replace vs add), billable, and duration, none of which are explained in the description. However, the schema does include some inline descriptions for the two required fields, providing baseline coverage.

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 "Update a time entry" uses a clear verb+resource pattern and correctly identifies the mutation operation. However, it doesn't distinguish this from sibling mutation tools like create_time_entry, and it doesn't specify which fields can be updated or whether updating differs from creating in scope. The purpose is adequate but minimal.

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?

No guidance is provided on when to use this tool versus alternatives. With 10 sibling time-related tools (create_time_entry, delete_time_entry, start_timer, stop_timer, get_time_entry), the description offers no differentiation or context for when an agent should choose update_time_entry over these. Notably, it doesn't clarify the relationship to timers (e.g., updating vs stopping a running timer).

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