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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuine context beyond that: figures derive from BowlPrice's own sampling of each brand's quote process, carry a last-verified date, and include links back to BowlPrice pages — enough for an agent to judge freshness and provenance.

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 sentences, front-loaded with what the tool returns before the provenance caveat. Slight redundancy — 'BowlPrice tracks' and 'BowlPrice's sampling' / 'BowlPrice's page' repeat the brand name three times — but nothing is padded.

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 must carry the return-value burden, and it does: unit costs, time horizons, ranking, verification dates, and per-brand links. It does not indicate result volume or whether brands with unavailable quotes are omitted, which is a minor remaining gap for a list-returning 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 enums and defaults documented in the schema itself (age bands, activity levels, neutering, weight range 2–60 kg). The description only reinforces the 'one dog' framing and does not add syntax or interaction details beyond the schema, so baseline 3 applies.

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 names the concrete output (cost per day, per month, first year), the exact population (every UK fresh and subscription dog food brand BowlPrice tracks), and the ordering (cheapest first). That is a specific resource and scope an agent can match a request against. It stops short of naming the sibling get_dog_food_price_history, so differentiation is left implicit (current cost comparison vs. historical pricing).

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?

Usage is only implied through scope constraints — 'for one dog', 'UK fresh and subscription', 'ranked cheapest first'. There is no explicit statement of when to reach for this instead of get_dog_food_price_history, and no note on when the result would be inappropriate (e.g. non-UK brands, raw/DIY feeding).

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