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

Annotations only cover the read-only/non-destructive safety profile, but the description adds real behavioral context: the earning model (95% of renter price, 30-day utilisation, validator idle rate), the fact that actual earnings and a provider middle-half range are returned, and the disclaimer 'An estimate, not a guarantee'. This goes well beyond what the annotations provide.

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 purpose is front-loaded and the when-to-use guidance follows, but the core sentence is a dense run-on stacking several clauses with semicolons. Every element earns its place, yet the middle section could be tightened.

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?

With no output schema, the description carries the burden of explaining returns and does so: rental income, idle pay, actual earnings, and the middle-half range across providers. Combined with the usage trigger and the 'estimate, not a guarantee' caveat, an agent has everything needed to call and interpret it.

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 gpu and count are already documented with examples and defaults in the schema. The description only loosely references 'GPUs of a model' and never mentions the count parameter, so it adds no meaningful semantics beyond the schema.

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 ('Estimate what a provider earns per month on Lium') and details the computation model, including rental income at 95% of renter price, idle pay, and the middle-half range. An agent can distinguish it from siblings like get_gpu_prices or search_gpus without opening the schema.

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?

Explicitly states when to use it ('Use when someone asks what their GPUs could earn on Lium') and names the alternative for a different intent ('for renting GPUs use search_gpus'). Both the trigger and the exclusion are stated.

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