get_entities

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

With zero annotations, the description carries the full burden and does meaningful work: it discloses that parent_id is required, that campaign_criterions excludes Audience (which is 'not readable via this API'), and the notable quirk that campaign BiddingScheme reads as None on MS while the effective strategy lives on ad_groups. These are genuine behavioral disclosures beyond a plain 'fetch'. It stops short of covering pagination, limits, or result format.

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 main action and entity list are front-loaded, with constraints and caveats appended in a logical order. Every sentence carries information — the entity enumeration, the parent_id rule, the criterion-type restriction, and the BiddingScheme quirk all earn their place. It's dense but not padded.

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 3-parameter tool with no annotations and no output schema, the description covers entity values, the parent_id requirement, and the two notable API quirks. The gap is the undocumented `ids` parameter, and with no output schema the return format for each entity type is unstated, which an agent would need to know to use results downstream.

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. It documents `entity` by listing valid values and `parent_id` by stating the 'required for all but campaigns' rule, which is real added meaning. However, `ids` is left completely unexplained — the schema only shows a nullable integer array defaulting to null, and the description never clarifies whether omitting it lists all rows or fetches a single entity.

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 uses a specific verb-resource pair ('Fetch entity state') and enumerates the exact supported entity types (campaigns, ad_groups, keywords, ads, asset_groups, campaign_criterions), which distinguishes it from the specialized sibling getters like get_negative_keywords and get_conversion_actions. It's slightly vague on what 'state' means, but the entity enumeration gives sufficient specificity.

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?

The constraints (parent_id required for all but campaigns; Audience not readable; BiddingScheme reads as None) imply usage context but are procedural constraints, not tool-selection guidance. It never explicitly says when to prefer this generic getter over specialized getters or run_report, so an agent would have to infer the routing from the entity list alone.

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