session_form_fill

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

With no annotations, the description must carry the behavioral burden. It discloses that it fills all provided fields at once, that submit is clicked if the selector is set, and that session_start is required. However, it does not explain what happens on missing selectors, whether existing field values are overwritten, or how max_chars affects filling — notable for a mutation-oriented tool.

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?

The description is compact and front-loaded: it starts with the core operation, then defines key parameters, then a prerequisite. It uses a short pattern-list style that is easy to parse, though the Russian wording and lack of formatting boundaries between the parameter hints make it slightly less scannable than it could be.

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 multi-step form-filling tool, the description covers the essential command shape and one prerequisite, and an output schema exists to communicate return values. It omits details like the effect of max_chars, error behavior for invalid selectors, and whether the action fails if any field cannot be filled — leaving an agent to infer some runtime semantics.

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 0%, so the description must compensate. It explains fields as 'JSON {селектор: значение}' and submit as the send button selector — useful. But max_chars is undocumented in both schema and description, leaving one of three parameters unexplained.

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 clearly names the resource and action — 'Заполнить форму' (fill the form) — and the scope 'РАЗОМ' (all at once), which separates it from single-action typing tools like session_type or browser_type. It does not explicitly name a sibling as the alternative, but the intent is not ambiguous.

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 gives a clear usage context — 'Паттерн form filling' and 'Требует session_start' — so an agent knows this is for filling forms in one batch and requires an existing session. It does not explicitly contrast with session_type, session_click, or other alternatives, but the guidance is explicit enough.

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