get_evaluator

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

No annotations are provided, so the description carries the full burden, and it does a good job: it discloses exactly what is returned in each mode, that source is omitted unless version_id is set, that errors come back as a message, and the object-store side effect with an @obj_123 ID. It does not cover permissions or rate limits, hence not a 5.

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?

The first sentence is well front-loaded, but the piece is padded: the :param version_id line restates the opening paragraph, the :returns line restates the outcome, and the closing two sentences about the object ID duplicate the earlier object-store note. Structure is conventional but several sentences do not earn their place.

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?

With no output schema, the description must explain return values, and it does so for both modes plus the object-store preview and cross-function reuse. For a two-parameter read tool this is nearly complete; only permission/error-handling detail is missing.

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, and it does: both parameters are documented via :param lines, with version_id carrying real behavioral meaning (it controls whether python_code is returned). evaluator_id's semantics as "The Evaluator's id" is thin but adequate alongside the required-parameter constraint.

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 ("Fetches one Evaluator, or one of its versions with the Python source") and immediately distinguishes the two operating modes by the presence of version_id. It implicitly contrasts with the list_evaluators sibling via "one Evaluator," but never names the alternative 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?

Gives concrete conditional guidance: without version_id you get every version newest-first without source; with version_id you get that version's python_code, and it tells you to pass latest_version.evaluator_version_id to read current source. No exclusion or explicit alternative tool is named, but the when-to-use context is clear.

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