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

Annotations already say readOnlyHint=false and destructiveHint=true, so the description correctly aligns with a mutating operation. It adds useful behavioral context by disclosing the invoice restriction and the return value (previous and updated entry). It doesn't fully explain partial-update semantics, but the description still goes beyond the annotations.

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?

Three dense, purposeful sentences. The trigger is front-loaded, the precondition is next, and the limitation/return behavior follow without filler or redundancy.

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?

The description covers when to use, where to get the ID, an important business rule (invoiced entries), and the response shape. Given that there is no output schema and 10 parameters, it would be even stronger with a note about rate or partial updates, but it is still substantially complete for an editing tool.

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 0%, so the description must compensate. It names many relevant fields, but omits 'rate' and doesn't clarify value formats, duration syntax, or whether unspecified fields are preserved. It is helpful at the conceptual level but does not fully document all parameters.

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 uses a specific verb ('corrects') and resource ('existing entry'), and enumerates the editable fields (duration, description, project, date, times, tags, billable). It clearly differentiates from sibling tools like time.log_entry, time.delete_entry, and batch logging by emphasizing that this is for modifying an entry that already exists.

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?

It explicitly states 'Use this when the user corrects...' and gives the required precondition: the entry id from time.list_entries or a previous log result. It also provides a clear exclusion—cannot edit entries already on a sent invoice—along with what happens in that case.

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