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

With no annotations, the description carries the full burden. It discloses useful behavioral scope: limited panel, annualized EUR TTC figures, included sources and review dates, and that custom profiles/bulk export are unsupported. It says nothing about what happens with an unknown scenario_id, whether results are cached, or what the response shape is (no output schema exists).

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-loads what the tool does, then scope, then exclusions in tight fragments with no filler. The telegraphic style ('Limited panel, annualized EUR TTC costs, sources and review dates') is dense but readable; nothing is wasted.

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?

For a single-parameter read tool with no annotations and no output schema, the description adequately frames scope, data characteristics and limitations. However, the unexplained enum values and the absence of any return-shape hint leave real gaps an agent must fill by trial.

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?

There is one required parameter with 0% schema description coverage and an enum of opaque values ('small-base', 'hphc-6', 'hphc-9'). The description explains the general nature of a scenario but never decodes the enum — an agent cannot tell what 'hphc' means or how the sizes relate without guessing.

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: reading one documented electricity cost scenario, with a provenance note ('same verified source reader as the website'). The resource is clearly distinct from all siblings (consumption, addresses, cities, RGE companies, subscribe intent), though no sibling is named explicitly.

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 meaningful exclusions — 'Not a quote, market-wide ranking or subscription eligibility' and 'No custom profile or bulk export' — which steers an agent away from misusing it for ranking or eligibility questions. It stops short of naming the alternative tool (e.g. subscribe intent) for those excluded cases, so it is clear context without full routing.

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