navigate_back

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

The description discloses a key behavioral side-effect not captured in the annotations: it 'Invalidates current Page Map refs on success.' This is valuable context that helps the agent understand the tool's impact beyond the readOnlyHint/destructiveHint flags. There is no contradiction with the annotations.

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 two sentences long, front-loaded with the core purpose, followed by a necessary warning. Every sentence earns its place; there is no fluff or redundant information.

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, parameterless action, the description covers the essential context: what the tool does and what the agent must do after success (fetch fresh refs). The presence of an output schema obviates the need to explain return values, and the mention of get_page_map ties it to a sibling tool. This is complete for the tool's complexity.

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?

With zero parameters, the schema is fully covered and there is nothing for the description to elaborate on. The baseline for a no-parameter tool is 4, and the description appropriately focuses on behavior rather than parameter details.

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 states a specific action ('Navigate back to the previous page') with an explicit resource (browser history). This unambiguously distinguishes it from sibling tools like open_tab or switch_tab, which handle tab management rather than history navigation.

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 provides clear context that the tool is used for navigating back in browser history, and it gives an explicit post-success instruction ('Call get_page_map to get fresh refs'). However, it does not mention when not to use it or compare it directly to alternatives like open_tab or switch_tab, so it falls short of a full 5.

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