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

readOnlyHint=true already tells the agent this is a safe read. The description adds that 'menu' returns public/system prompts which can be narrowed by workspace, and that 'prompt_details' returns a prompt body, which is useful beyond the annotation. It says nothing about permissions, rate limits, or behavior when prompt_id is invalid.

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?

Two short numbered entries after a one-line purpose statement, with the mode-gating information front-loaded. Nothing is repetitive, though the second bullet packs a conditional into one sentence.

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?

An output schema exists, so return-shape explanation is unnecessary, and the description covers both request modes plus the workspace-scoping nuance. An agent could call it correctly; only edge cases (invalid prompt_id, prompt_type values) remain uncovered.

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 carries the burden, and it does clarify the role of workspace_id, prompt_type, prompt_id and is_custom in context. However, prompt_type's allowed values and the default behavior of is_custom when omitted go undocumented, leaving the compensating explanation partial.

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 ('Browse the Snapchat Ads prompt catalog') and then names the two operations, so an agent knows it reads a catalog rather than executing ads actions. It does not explicitly contrast with the generic siblings (query_data, execute_action), but the resource is distinctive enough to separate it.

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 numbered list maps each request value to its outcome, giving clear implied when-to-use guidance ('menu' for listing, 'prompt_details' for fetching a body). It also states the condition for is_custom + workspace_id. No explicit exclusions or prerequisites are given, so it falls short of a 5.

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