Set Extra Headers

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

No annotations exist, so the description carries the full burden, and it only says headers go into 'every outgoing request' — it never states whether the call replaces or merges with previously set headers, whether it applies only to the given tab_id or globally, whether it persists across navigations, or how to remove a header. The example's '{"set":[...]}' response does hint at the write result, but the mutation semantics an agent needs before calling are largely absent.

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 short blocks: a one-line statement of effect and a single concrete call/response example. Nothing is wasted and the primary behavior is front-loaded ahead of the invocation example.

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?

The output schema covers return values, so the example's response echo is a bonus rather than a necessity, and the example adequately demonstrates how to call the two-parameter tool. What is still missing for a mutation tool with zero annotations is the scope/persistence contract (per-tab vs global, merge vs replace), which an agent would need to use it safely.

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; the example does useful work by showing tab_id as a short tab handle ('t0') and the headers argument as a flat string-to-string map, plus echoing back which keys were set. It adds nothing about merge/override behavior or how to unset a header, leaving a real gap for the nested object parameter.

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 first sentence states a concrete verb and effect (inject headers into every outgoing request) and the example pins it to a specific tab ('t0') plus header pairs, so an agent knows exactly what the tool does. It stops short of differentiating from header-capable siblings such as route_add or set_cookies, so it is clear but not sibling-aware.

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 fragment 'Auth, A/B flags, tracing' hints at intended scenarios, which gives implied usage guidance. There is no explicit when-to-use/when-not statement and no mention of alternatives (e.g., route_add) for achieving similar header mutation, so the agent must infer the routing decision.

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