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

With no annotations, the description carries the full burden and does it well: it discloses that the profile is an estimate rather than Smart Meter Texas interval reads, explains the modeled fallback behavior, promises to say so, commits to never storing or repeating the street, and notes the verified_as_of field. These are meaningful behavioral details beyond the schema.

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?

Five short sentences, front-loaded with the core purpose, then usage guidance, then caveats. Every sentence adds distinct value and there is no redundant or filler content.

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?

Given no output schema, the description provides strong context: what the tool ranks, when to use it, data provenance, fallback behavior, privacy, and an output field. It does not fully describe the ranking result shape, but the detail parameter and verified_as_of note cover most of what an agent needs.

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%, so the baseline is 3. The description adds context about the usage profile and privacy handling, but it does not add independent semantic detail about the params themselves; the schema already documents each parameter clearly.

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 states a specific verb and resource: 'Rank certified Texas electricity plans for a street address using a twelve-month usage profile.' It immediately distinguishes itself from sibling compare_plans by the presence of an address, so an agent can tell them apart 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?

It explicitly instructs to 'Prefer this over compare_plans when the user has an address,' giving a clear routing rule relative to a sibling. It also explains the fallback when no usage history exists, which informs when the tool can still be used.

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