Create a reusable evaluation bench

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the mutation profile is covered. The description adds genuinely non-obvious context: no model calls/cost, the name must be unique among registered benches, and saving registers the bench immediately (a real side effect). It does not, however, state what happens on name collision beyond the schema's 'Fails if...', or whether a bench can be deleted/updated later.

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-loaded with the highest-value fact ('Free, local, no model calls'), then purpose, then integration and constraints. Three sentences mostly earn their place, though 'saving registers the bench immediately' partially repeats the opening 'Saves a new reusable bench' and the confirmation guidance.

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 an output schema present, return values need not be explained. The description covers cost, persistence, naming constraints, downstream consumption, and the user-confirmation workflow — everything an agent needs to call a 3-param, nested-schema creation tool correctly.

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 goes beyond the schema by tying the `name` parameter to its downstream usage form (plugin: "<name>") and by reinforcing the uniqueness constraint on names, which is the parameter most likely to cause a failure.

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+resource ('Saves a new reusable bench') and immediately defines what a bench is ('a named set of scenarios and scoring criteria'). It clearly distinguishes itself from sibling read tools like tournament_list_benches by naming exactly what it creates and who consumes it.

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 an explicit precondition ('Draft the scenarios and criteria first and confirm them with the user before calling this tool') and names the two downstream tools (tournament_evaluate, tournament_quick_test) plus the discovery path (tournament_list_benches). An agent knows exactly when and when not to call it.

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