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

Big-ticket behaviors the annotations cannot express are disclosed: ~$0.10 per image cost, per-person and per-workspace rate limits, the no-retry-in-a-loop rule, the replacement semantics that can overwrite a human-uploaded cover, and the cover_exists refusal. It also preempts a likely misuse of the public_projection_synced flag, which annotations say nothing about.

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?

Front-loaded with the purpose and the one-per-dataset constraint before branching into cost, replacement and parameter nuance. It is long, but almost every sentence carries an actionable constraint; the return-value enumeration and visibility aside are the only portions that run a little past what an agent strictly needs.

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 enumerates the returned fields and explains the two ambiguous ones (visibility enum values, and that public_projection_synced does not mean public). Combined with cost, rate-limit, refusal-code and idempotency guidance, an agent has everything needed to call this correctly and interpret the result.

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 full burden and does: subject is defined as plain-language content (place/instrument/phenomenon) with explicit exclusions for style, colour and size, plus what happens if omitted; replace and idempotency_key are both explained in terms of the person's intent. Only dataset_id is left implicit, and its role is obvious from context.

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 ('Generates the dataset's branded 1200×630 cover and attaches it') and immediately scopes it as a one-per-dataset artifact. It also distinguishes itself from lookalike siblings, warning not to follow with update_dataset and routing visibility changes to set_dataset_visibility.

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 explicit preconditions and exclusions: call only when get_my_dataset reports has_cover=false, expect refusal code cover_exists otherwise, and pass replace:true only when the person explicitly asks. Names the alternative tools (get_my_dataset, set_dataset_visibility) and the exact retry path via idempotency_key.

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