pane_set_symbol

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

Annotations already cover mutation safety (readOnly=false, destructive=false, idempotent=false), so the description earns credit for the extra context it does add: the write is followed by verification of the resolved instrument and detection of collateral pane changes, i.e., this can ripple into other panes. It does not cover failure behavior or what the verification returns, keeping it below 5.

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?

A single front-loaded sentence: action and scope first, then the verification and side-effect guarantees. No filler, nothing redundant.

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 non-idempotent mutation with no output schema, the description covers the critical hidden behavior (cross-pane side effects, post-write verification) and the layout guard lives in the schema. Minor gaps remain around failure modes and the optional parameters, but an agent can call it 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 coverage is only 33%, so the description carries real weight — "exchange-qualified symbol" usefully explains the EXCHANGE:SYMBOL pattern, "exactly one pane" clarifies that index addresses a single pane, and "collateral pane changes" hints at allow_linked_changes. But index bounds, timeout_ms, and the semantics of allow_linked_changes remain undocumented, so it only partially compensates.

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 ("Set an exchange-qualified symbol") plus a precise scope ("exactly one pane"), and adds two post-conditions (verify resolved instrument, detect collateral changes). The pane-level scope implicitly contrasts with the chart-level sibling chart_set_symbol, but no sibling is named, so it falls just short of a 5.

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 only implied: the "exactly one pane" framing suggests this is the tool for per-pane symbol changes rather than whole-chart changes, but the description never says when to use it instead of chart_set_symbol or pane_set_timeframe, nor does it state preconditions. An agent must infer the routing.

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