session_info

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description earns credit by adding non-obvious runtime context the annotations cannot: Electron runs its bundled Chromium rather than installed Chrome, and CDP lacks Electron main-process/Menu APIs — information that directly prevents wrong assumptions when planning later calls.

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?

Three short sentences, front-loaded with what is returned and followed by the two caveats that matter most. No filler or repetition; the only shortfall is that brevity comes at the cost of the missing sessionId explanation.

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 simple single-parameter read-only inspection tool with no output schema, enumerating the categories returned (transport, ownership, runtime versions, capabilities) is largely sufficient, and the caveats cover the main misuse risk. The remaining gap is the unexplained sessionId requirement, which the agent must infer from sibling tools.

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 exactly one required parameter, sessionId, with 0% schema description coverage, and the description never mentions it — no indication of where a sessionId comes from (presumably session_start/session_list) or whether it must be an active session. The single parameter is left entirely undocumented in both structured data and prose.

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?

"Show the actual session transport, ownership, runtime versions and capabilities" gives a specific verb plus an enumerated set of returned fields, which is far more concrete than the bare name session_info. It is clearly a read-only inspection tool, distinguishable from siblings like session_list or session_start, though it never names those siblings 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?

Usage is implied rather than stated: the Electron/Chromium and CDP caveats signal that this tool should be consulted before assuming a Chrome or CDP-specific capability exists. There is no explicit when-to-use, when-not-to-use, or routing to session_list/session_start for other needs.

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