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

No annotations, so the description carries the full burden; it implies a read-only lookup but never says so. It discloses no time horizon, number of slots returned, price units, rate limits, or auth error behavior for a paid-tier endpoint.

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?

A single front-loaded sentence with no waste. The 'PRO.' fragment is efficient shorthand for tier gating, though slightly opaque.

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 and no annotations, the description should explain what comes back (slot list, price unit, window length) and how this differs from all_slots or best_window. It leaves an agent unable to predict the response shape for a data-returning pricing tool.

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%, with postcode and access_token both documented inline, so the baseline is 3. The description adds nothing about how postcode affects region or how the subscriber token is obtained.

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 resource (Agile Outgoing export prices) and scope (best upcoming slots to sell solar/battery power), which distinguishes it from cheapest_slots and daily_average well enough. The 'PRO.' prefix implies a paid tier but is otherwise cryptic.

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?

No guidance on when to use this versus siblings like best_window, cheapest_slots, or all_slots, and no stated prerequisites beyond the token being mentioned in the schema. The agent must infer selection from the tool name alone.

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