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

Annotations already state readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the agent knows this is a pure, safe computation. The description's 'swap rows and columns' adds a small semantic clarification but says nothing about error behavior on ragged or empty matrices — the main behavioral risk for this 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?

One short, front-loaded sentence with zero filler; the operation is stated first and the parenthetical gloss immediately follows. Appropriately sized for a single-parameter pure math operation.

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 simple, annotation-covered, output-schema-backed pure function, the description is sufficient to call it correctly. The only missing piece an agent might want is input validation behavior for non-rectangular matrices, which is a minor omission.

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% with a worked nested-array example for the single 'matrix' parameter, so the schema fully carries parameter semantics. The description adds nothing about input shape (2-D array of numbers) beyond the word 'matrix', which is the expected baseline.

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?

Gives a specific verb ('transpose') and resource ('a matrix') plus a plain-language gloss ('swap rows and columns') that removes ambiguity about what the operation does. It is clearly distinguishable from sibling matrix tools (add, multiply, inverse, determinant) by the verb itself, though it never names or contrasts them explicitly.

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 on when to use this vs. calculator_matrix, calculator_matrix_inverse, or calculator_determinant, and no stated preconditions (e.g., whether ragged/rectangular inputs are accepted). The agent must infer usage entirely from the operation name.

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