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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is fully covered. The description reinforces this with 'reads nothing from the CRM, calls no provider, and spends nothing,' which adds a cost guarantee not present in annotations, but it does not disclose return shape, entry count, or caching/staleness behavior. With annotations carrying the main burden, this is adequate reinforcement rather than rich added context.

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 description is front-loaded with purpose, then when-to-call, then concrete examples of counter-intuitive values. Every sentence contributes, though the phrasing is dense and the parenthetical analogies to list_filterable_fields make it longer than strictly necessary for a one-parameter read-only list.

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 single-parameter, read-only lookup with no output schema, the description fully explains what comes back (criteria, meanings, cardinality, allowed values) and why it matters. Nothing an agent needs in order to call it correctly or to interpret the result 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 100% and the single object_type parameter has its enum and description ('Which object the create run targets. Contact only.') documented in the schema. The description adds no syntax or format detail beyond what the schema already provides, so the baseline 3 applies.

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 names a specific resource (the search criteria create_records_run accepts) and enumerates what each entry carries: meaning, multi-value behavior, and fixed allowed values. It distinguishes itself from siblings by explicitly likening its role to list_filterable_fields while being about create_records_run search criteria, so an agent can place it without opening a 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?

It gives an explicit directive ('CALL THIS BEFORE COMPOSING A SEARCH rather than guessing') and states the failure mode that motivates it: the provider rejects unrecognised values at dispatch, after a run has been created and possibly approved. It also points to list_filterable_fields as the analogous tool for filters, so when-to-use and when-not-to-guess are both covered.

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