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

Annotations declare a non-read-only, non-destructive, non-idempotent write, and the description adds genuinely useful behavioral context beyond that: setting the language changes field-name casing and code examples produced by other tools. It still omits whether state persists across sessions and how node_url/node_type alter downstream output.

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 tight sentences with the operation and the highest-value side effect front-loaded; nothing is padded or redundant at the sentence level.

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 and annotations covering the mutation profile, the description need not explain return values, and the casing behavior is captured. The main remaining gap is the absence of guidance on when session preferences matter for downstream calls.

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% and all six parameters, including enums and the preferences handle precedence rule, are documented in the schema. The description's casing note duplicates the language parameter's own schema text, adding no new parameter meaning, so the 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?

States a specific dual verb (get/set) and the exact resource (session preferences) plus the fields it governs, which separates it cleanly from decode/explain/explore/list/lookup/search siblings. It does not explicitly name a sibling, but the resource is distinct enough that confusion is unlikely.

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?

The description never says when to get versus set, when preferences are needed at all, or how this interacts with the other subtensor_* tools. Usage is only implied by the 'get or set' phrasing, and the 'preferences' handle alternative is explained only in the schema, not the description.

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