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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, which fully covers the safety profile of a pure computation, so the bar is lower. The description usefully confirms the tool suggests a disk size (a derived output) and never mutates anything, but adds no detail on precision, units, or rounding.

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 core sentence is well front-loaded and efficient, but the second sentence is pure external-link trivia that earns no place in a tool definition since an agent cannot use the URL.

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 33% parameter coverage, the description should carry the burden of explaining inputs and the shape of the result. It names only the two headline outputs and omits parameter meaning and return detail, leaving the agent under-equipped.

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 only 33%, so half-plus of the six parameters (codec, resolution, hoursPerDay, cameras) rely on the agent inferring meaning. The description supplies no parameter guidance at all, failing to compensate for the coverage gap.

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 (estimate) and resource (hard-disk storage a CCTV system needs) plus a concrete secondary output (suggest a disk size). This is clearly distinguishable from the sibling calculate_ups_backup, and an agent can route on it without opening the 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?

No when-to-use guidance, no mention of the sibling calculate_ups_backup or how to choose between the two calculators, and no prerequisites. The URL reference does not function as usage guidance for an agent.

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