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

The all-caps claim 'NON-DESTRUCTIVE' sits in direct tension with the annotation destructiveHint=true (setting a cell overwrites the previous value). The description does scope the term by saying identity and trace links survive, which limits the harm, but an agent skimming annotations versus the description gets conflicting signals about whether data is destroyed. On non-conflicting points it is rich (normalisation rules per column type, which cells are settable), but the destructive-wording conflict is a real inconsistency.

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?

Front-loads the core operation and the required identifiers, then adds behavioural detail. It is dense (one long paragraph with stacked clauses), but essentially every clause carries actionable information; minor tightening possible.

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?

No output schema exists, and the description covers the mutation, its scoping, the identifier alternatives, and the 'not settable here' exclusion. It omits permissions/error behaviour, and the destructive-vs-non-destructive framing needs reconciliation with the annotations, so not quite complete.

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, and the description goes beyond it by explaining that row identity may be given as itemId or atOrder (one of the two), that colIdx is 0-based, and that the meaning of `value` varies by column type (raw for id/text, PASS/FAIL normalisation for test-result, true/yes/1/✓ for checkbox, chosen option for dropdown). That is meaningful value semantics the schema's generic 'The new cell value' does not convey.

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+resource+scope: sets ONE cell of an ID grid, identified by id-ROW (itemId or atOrder) and a 0-based colIdx. It also explicitly distinguishes itself from siblings (traceable_segment_write for the id column, traceable_link for link cells), so an agent can tell it apart without opening another schema.

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?

Gives explicit routing rules: link cells are not settable here, use traceable_link instead; and contrasts with traceable_segment_write for the id column. The when-to-use condition (set a single cell value, including the visible TraceID, while keeping links) is unambiguous.

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