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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, so the safety profile is covered by structured data. The description contributes the write-scope requirement, which is genuinely additive, but says nothing about partial-update semantics (only 'id' is required) or what an update overwrites — notable for a tool annotated as destructive.

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 compact sentences, operation stated first, prerequisite second. Nothing redundant and no filler.

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 destructive mutation with no output schema, the description covers identity and authorization but omits the key behavioral question an agent needs: whether omitted fields are preserved or cleared (partial vs. full replace). Annotation coverage of the safety profile keeps this from being a larger gap.

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 100% with 10 well-documented properties, including the nuanced duration_minutes note about agreeing with start/end times. The description adds no parameter meaning beyond the schema, so the baseline 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?

States a specific verb and resource ('Update an existing project time entry') and the lookup key ('by ID'), which cleanly separates it from create_project_time_entry and delete_project_time_entry. It does not differentiate itself from the other ~90 'update_*' siblings, but the resource noun is unambiguous.

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 only usage context given is the required OAuth scope, which is a permission prerequisite rather than guidance on when to pick this tool over alternatives (e.g. bulk_update, or delete/re-create). No when-to-use or when-not-to-use conditions are stated.

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