last_error

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered by structured data. The description adds nothing beyond that: it does not say whether reading consumes/clears the error, how long the error is retained, or what the error payload looks like. It does not contradict 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?

A single short sentence with no filler, front-loaded and readable. It is arguably under-specified rather than over-long, but as a zero-parameter getter the brevity is close to appropriate.

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 zero-parameter getter with full annotation coverage, the definition is minimally adequate. However, there is no output schema, and the tool's whole value is the shape/content of the returned error object (severity, timestamp, message), which the description never characterizes.

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?

The tool takes no parameters, so the baseline is 4. There is nothing for the description to compensate for, and no parameter confusion is possible.

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 ('Последняя ошибка runtime и Application.getLastError') is effectively a translation of the tool name 'last_error', i.e. a restatement of the resource rather than a verb+resource statement. It does add the qualifier 'runtime' and the reference to Application.getLastError, but there is no explicit 'returns/get' verb and little to distinguish it from siblings like health_check or repair_hints.

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 when-to-use, when-not-to-use, or alternative guidance is given. An agent cannot tell from the text whether this should be consulted before repair_hints, after execute failures, or at any other point in the workflow.

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