create_run_long_workout

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

With no annotations, the description carries the full behavioral burden. It does add real value by disclosing the upload side effect and the custom HR-band encoding detail (targetValueOne/Two, device showing '130-145 bpm' instead of 'Zone X'). But it omits auth/permission requirements, whether the upload is immediate or reversible, and failure behavior for a mutating, remote-upload tool.

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?

Purpose is front-loaded in the first sentence, followed by the differentiating HR-band detail and a clean Args list. The encoder-bug sentence is implementation trivia but earns some place by explaining why the tool exists; overall it is tight and skimmable.

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?

An output schema exists, so return values need not be explained, and the description covers all parameters plus the notable upload side effect. The main remaining gap is the absence of any sibling differentiation, which matters given how crowded the create_*_workout family is.

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 — and it does: the Args section documents all six parameters with units and defaults (hr_min 130, hr_max 145, warmup_min 10, cooldown_min 10), and the HR-band paragraph explains what hr_min/hr_max actually produce on-device. It stops short of stating valid ranges or constraints.

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 states a specific verb and resource ('Create a long run ... upload it to Garmin Connect') and the opening sentence makes the outcome clear. However, it never distinguishes this from the many sibling workout creators (create_run_easy_workout, create_run_tempo_workout, create_run_intervals_workout, create_run_workout, etc.), so an agent must infer the distinction from the name alone.

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 by the word 'long run' — the description gives no explicit when-to-use versus when-not, and does not route to any of the ~10 similar run/workout creation siblings. There is no prerequisite or exclusion guidance, so the agent must infer context.

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