herdr_open_agent

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

Annotations already declare destructiveHint=true, openWorldHint=false and non-idempotency, so the safety profile is partly covered. The description adds that the call opens both a tab and a pane and spawns an agent process, but does not explain the destructive/state-creating implication, focus stealing, or what happens on startup timeout, which would be useful beyond 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?

Two short sentences, action front-loaded, with the differentiator ('one-call') placed after the core verb. No wasted text.

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 nine-parameter tool with no output schema, the description covers intent but omits what is returned (presumably an agent name/id needed by herdr_agent_prompt, herdr_agent_read, herdr_agent_wait) and says nothing about failure modes such as the startup timeout. Adequate but with clear gaps.

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 100%, so all nine parameters are already documented in the input schema (including the HERDR_MCP_ALLOW_AGENT_ARGS gate on agent_args). The description only echoes the optional prompt, adding no format or default detail beyond the schema, so the baseline 3 applies.

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 compound action: open a new tab and pane and start a coding agent, optionally with a prompt. The phrase 'The one-call way to launch an agent in a fresh tab' signals it differs from herdr_tab_create + herdr_pane_split + herdr_agent_start, but never names those siblings.

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 one-call way to launch an agent in a fresh tab' implies the usage context (new tab/pane versus an existing one), but there is no explicit when-to-use/when-not, no mention of herdr_agent_start for the in-place case, and no stated prerequisites.

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